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  • 1.
    Alici, Gursel
    et al.
    School of Mechanical, Materials, and Mechatronic Engineering, ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, Australia.
    Mutlu, Rahim
    School of Mechanical, Materials, and Mechatronic Engineering, ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, Australia.
    Melling, Daniel
    Institute for Medical Science and Technology, University of Dundee, Dundee, UK.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Kaneto, Keiichi
    Kyushu Institute of Technology, Eamex Co. Ltd, Chuoku, Fukuoka, Japan.
    Conducting Polymers as EAPs: Device Configurations2016In: Electromechanically Active Polymers: A Concise Reference / [ed] Federico Carpi, Cham: Springer, 2016, p. 257-292Chapter in book (Other academic)
    Abstract [en]

    This chapter focuses on device configurations based on conjugated polymer transducers. After the actuation and sensing configurations in the literature are presented, some successful device configurations are reviewed, and a detailed account of their operation principles is described. The chapter is concluded with critical research issues. With reference to the significant progress made in the field of EAP transducers in the last two decades, there is an increasing need to change our approach to the establishment of new device configurations, novel device concepts, and cutting-edge applications. To this aim, we should start from the performance specifications and end up with the material synthesis conditions and properties which will meet the performance specifications (top-to-down approach). The question should be “what electroactive material or materials can be used for a specific purpose or application,” rather than looking for an application or a device concept suitable to the unique properties of the EAPs and transducers already made of these materials. The field is mature enough to undertake this paradigm change.

  • 2.
    Amaia Beatriz, Ortega-Santos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Enzymatic biofuel cells embedded polymer-based soft actuators2022Conference paper (Other academic)
    Abstract [en]

    Enzymatic biofuel cells are presented as an untethered alternative energy source that could power small implantable or wearable medical devices. However, most of these catalytic processes do not provide with enough energy to power common small electronic-mechanical devices. On the other hand, conducting polymer-based actuators are of great interest for their biocompatibility, flexibility, processability, possibility to be miniaturized and low power consumption. So far, these artificial muscles have been driven by external power sources that prevent them for being completely autonomous. There is a need for a novel power source to elaborate actuators that could use physiological processes as a driving force. These soft actuators’ low power consumption matches the electrical power generated by the biocatalysis of some enzymes, such as glucose oxidase and laccase in presence of glucose and oxygen in aqueous media. Here, we present the latest results in the development of polypyrrole-based soft actuators powered by enzymatic biofuel cells. The actuator consists of a tri-layer conductive substrate on which the polypyrrole is electrodeposited in both sides. The polypyrrole layers act as the active part, expanding and contracting upon a redox reaction, resulting in a bending movement. Tetrathiofulvlene-7,7,8,8-tetracyanoquinodimethane (TTF-TCNQ) and 2,2′-azino-di-(3-ethylbenzthiazoline sulfonic acid) (ABTS) electron transfer mediators are cast on the surface of the polypyrrole to help the electron transmission. The glucose oxidase and laccase enzymes are immobilized in the modified-conducting polymer surface, integrating the electrode to the actuator. The bio-catalysis of enzymes in presence of glucose and oxygen in aqueous solution provides the actuator with the electrons needed for the redox reaction, converting the chemical energy into mechanical energy, i.e., movement. The glucose-self-powered soft actuator may contribute to the development of more complex implantable, ingestible, or wearable biomedical devices such as cardio-stimulators, insulin pumps, or muscle implants.

  • 3.
    Amaia Beatriz, Ortega-Santos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    The effect of enzyme immobilization methods in polypyrrole-based soft actuators driven by glucose and O22023Conference paper (Other academic)
  • 4.
    Arwin, Hans
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Schoeche, Stefan
    JA Woollam Co Inc, NE 68508 USA.
    Hilfiker, James
    JA Woollam Co Inc, NE 68508 USA.
    Hartveit, Mattias
    Univ Rochester, NY 14627 USA.
    Järrendahl, Kenneth
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Juarez-Rivera, Olga Rubi
    Cinvestav Queretaro, Mexico.
    Mendoza-Galvan, Arturo
    Cinvestav Queretaro, Mexico.
    Magnusson, Roger
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Optical Chirality Determined from Mueller Matrices2021In: Applied Sciences, E-ISSN 2076-3417, Vol. 11, no 15, article id 6742Article in journal (Refereed)
    Abstract [en]

    Featured Application The analysis of the transmission of Mueller matrices facilitates studies of optical activity in samples that also exhibit linear anisotropy and depolarization and may have a multilayered structure. Such studies are important for the development of applications in chiroptics. Optical chirality, in terms of circular birefringence and circular dichroism, is described by its electromagnetic and magnetoelectric material tensors, and the corresponding optical activity contributes to the Mueller matrix. Here, spectroscopic ellipsometry in the spectral range 210-1690 nm is used to address chiral phenomena by measuring Mueller matrices in transmission. Three approaches to determine chirality parameters are discussed. In the first approach, applicable in the absence of linear polarization effects, circular birefringence and circular dichroism are evaluated directly from elements of a Mueller matrix. In the second method, differential decomposition is employed, which allows for the unique separation of chirality parameters from linear anisotropic parameters as well as from depolarization provided that the sample is homogeneous along the optical path. Finally, electromagnetic modeling using the Tellegen constitutive relations is presented. The last method also allows structural effects to be included. The three methods to quantify optical chirality are demonstrated for selected materials, including sugar solutions, alpha-quartz, liquid crystals, beetle cuticle, and films of cellulose nanocrystals.

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  • 5.
    Aziz, Shazed
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Salahuddin, Bidita
    Australian Institute For Innovative Materials University Of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2522, Australia.
    Persson, Nils-Krister
    Smart Textiles Technology Lab Swedish School Of Textiles University Of Borås Borås SE-501 90, Sweden.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    PEDOT:PSS coated twisted and coiled yarn actuators2021In: EuroEAP 2021: International conference on Electromechanically Active Polymer (EAP) transducers & artificial muscles, 2021Conference paper (Other academic)
    Abstract [en]

    Commercial yarns can be functionalized with conducting polymers (CPs) todevelop yarn and textile actuators. Here we show a method of functionalizationof commercial polyamide yarns by poly-3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) coating. Aftercoating, while PEDOT:PSS is drying, it is possible to twist and coil the yarns,resulting in a major improvement of their linear strain and speed of movement.By using a potential window between +0.6 V and -1.2 V vs Ag/AgCl it waspossible to obtain a fully reversible actuation of a coiled yarn providing up to1.62% strain. A strain higher than 1% was achieved in less than 1 second.Compared to the untwisted, regular yarns, the twisted and coiled yarns produce>9× and >20× higher strain, respectively. These results are a step forward towardsthe development of soft, silent and compliant smart textile exoskeletons.

  • 6.
    Backe, Carin
    et al.
    University of Borås.
    Guo, Li
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Persson, Nils-Krister
    University of Borås.
    Towards responding fabrics – textile processing of thin threadlike pneumatic actuators2019Conference paper (Other academic)
    Abstract [en]

    With few exceptions (such as 1) textiles have not been considered as means for obtaining actuation. This is surprising as textiles have many advantageous characteristics such as the D=M property, which stands for Doing Devices while Making the Material. This means that functions are introduced simultaneously as the material, such as in a weave, is built up tread by tread. Traditionally a tread could have a certain colour so in total an aesthetical pattern is formed. Now we take a step beyond this working with threads having more advanced functions. Included are fiber formed structures showing actuation behavior. 

    This we employ here. We make fiber formed actuating structures (FAS) following the McKibben principle (2) with braided mesh sleeves surrounding a prolonged inflatable tube. Here we worked with relatively large diameters in the relaxed state but show that there is prospect for obtaining relaxed diameters of less than 1 mm approaching the range of large scale weaving manufacturing.

    We study the behavior of these fibre formed actuating structures individually. Length changes obtained are -20%. We then make textile constructions by integrating several of these FASes with textile processing. By this, we build simple models of fabrics showing actuating behavior.  

     

    This study shows how textile constructions can support or hinder overall movement. It is a first logical step in order to get an understanding of actuating fabrics based also on other actuating mechanisms (3).

  • 7. Backe, Carin
    et al.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Guo, Li
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Persson, Nils-Krister
    Multi-Assembly of Soft Electroactive Polymeric Yarn Actuators by Using Textile Processes2021Conference paper (Other academic)
  • 8. Backe, Carin
    et al.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Guo, Li
    Persson, Nils-Krister
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Serially connected EAP based tape yarns for in-air actuation using textile structures2023Conference paper (Other academic)
  • 9.
    Bakoglidis, Konstantinos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. Univ Manchester, England.
    Palisaitis, Justinas
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    dos Santos, Renato B.
    Univ Fed Bahia, Brazil.
    Rivelino, Roberto
    Univ Fed Bahia, Brazil.
    Persson, Per O A
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Gueorguiev, Gueorgui Kostov
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Self-Healing in Carbon Nitride Evidenced As Material Inflation and Superlubric Behavior2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 19, p. 16238-16243Article in journal (Refereed)
    Abstract [en]

    All known materials wear under extended mechanical contacting. Superlubricity may present solutions, but is an expressed mystery in C-based materials. We report negative wear of carbon nitride films; a wear-less condition with mechanically induced material inflation at the nanoscale and friction coefficient approaching ultralow values (0.06). Superlubricity in carbon nitride is expressed as C-N bond breaking for reduced coupling between graphitic-like sheets and eventual N-2 desorption. The transforming surface layer acts as a solid lubricant, whereas the film bulk retains its high elasticity. The present findings offer new means for materials design at the atomic level, and for property optimization in wear-critical applications like magnetic reading devices or nanomachines.

  • 10.
    Bentzer, Justinius Erik
    Linköping University, Department of Management and Engineering, Carl Malmsten - furniture studies. Linköping University, The Institute of Technology.
    Textil, faner och jag: en möbelkollektion sprungen ur en undersökning av materialkombinationer faner och textil2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Jag har ett intresse för att utforska och undersöka olika material och hur vi upplever dessa material. I detta examensarbete skapar jag två möbler genom en gestaltningsprocess som grundar sig i ett undersökande av materialkombinationen faner och textil. Arbetet är uppdelat i två delar, en undersökande del där jag testar att kombinera olika faner, textilier och limmer, för att se hur jag upplever dessa och för att få en grund till min gestaltningsprocess. I den andra delen formger jag två möbler som har till syfte att väcka intresse för materialet hos betraktaren. Det blir ett klädskåp och en sittmöbel, som visar på olika sido !och mervärden med materialkombinationerna. Förhoppningsvis kan detta  arbete väcka intresset för nya materialkombinationer även hos er läsare.

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  • 11.
    Boda, Ulrika
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Screen Printed Stretchable Electronics2023Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wearable electronics that can be seamlessly integrated into clothing, onto skin, or inside the body, can enable a variety of novel applications within healthcare monitoring, biosensing, biomedical devices and the internet of things. Seamless integration requires matching of the mechanical properties of the electronics to clothing, skin, and tissues, i.e., the electronics need to be soft, flexible, and stretchable. One approach to achieve this is to make all or most components of a device stretchable in themselves by developing functional intrinsically stretchable composites. Such composites are typically based on a filler, which provides electronic or other functionality, and an elastomer matrix, which provides the mechanical properties of the composites. Manufacturing of intrinsically stretchable electronics is challenging and often involve time consuming and tedious fabrication procedures of low throughput, based on chemically harmful monomers and solvents. An alternative approach, printing of electronics, has experienced a boom in the past decade, recently even for stretchable applications. However, despite its appeal, stretchable printed electronic products have yet to reach the consumer market in larger numbers. Screen printing is a versatile printing method that is cost-effective, scalable, can be tailored to use harmless solvents with little waste, and can be made environmentally friendly by careful choice of materials. Furthermore, some applications of stretchable technology – such as implants and on-skin electronics – require conductors that are stable under humid, corrosive, or polluted conditions, which puts even more weight into choices of ink components.

    In paper I, we protected readily available conducting silver flakes through a thin coating with gold in a low-toxicity water-based process and demonstrated its use in inks for screen printed corrosion-resistant stretchable conductors. The novel silver-gold flake ink was used to fabricate a functional stretchable near-field communication device. Papers II and III both concern entirely screen printed and inherently stretchable devices, utilizing novel stretchable inks in combination with commercial inks to print vertical stacks. Two electrochemical devices – electrochromic displays and organic electrochemical transistors – were printed and tested under stretched conditions to push the limits of how screen printing can be used in applications for thin and stretchable wearable technology. The results show that the devices can retain electrical function even under practically high strains of 50 % (display) and 100 % (transistor). Finally, in paper IV, we investigate the operational principle of gold nanowire- based stretchable composites and find that interactions on the nano-and microscale differ between composites using the same filler but different elastomers. This study sheds light on the importance of the type of elastomer chosen for composites, as this heavily influences the composite’s electrical performance under strain.

    Altogether, the studies presented in this thesis provide knowledge, materials, and processes that in the long run can contribute to more effective devices within healthcare and other wearable electronics applications.

    List of papers
    1. Fully screen printed stretchable electrochromic displays
    Open this publication in new window or tab >>Fully screen printed stretchable electrochromic displays
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    2021 (English)In: Flexible and Printed Electronics, ISSN 2058-8585, Vol. 6, no 4, article id 045014Article in journal (Refereed) Published
    Abstract [en]

    The advent of the Internet of Things and the growing interest in continuous monitoring by wearables have created a need for conformable and stretchable displays. Electrochromic displays (ECDs) are receiving attention as a cost-effective solution for many simple applications. However, stretchable ECDs have yet to be produced in a robust, large scale and cost-efficient manner. Here we develop a process for making fully screen printed stretchable ECDs. By evaluating commercially available inks with respect to electromechanical properties, including electrochromic PEDOT:PSS inks, our process can be directly applied in the manufacturing of stretchable organic electronic devices. The manufactured ECDs retained colour contrast with useful switching times at static strains up to 50% and strain cycling up to 30% strain. To further demonstrate the applicability of the technology, double-digit 7-segment ECDs were produced, which could conform to curved surfaces and be mounted onto stretchable fabrics while remaining fully functional. Based on their simplicity, robustness and processability, we believe that low cost printed stretchable ECDs can be easily scaled up and will find many applications within the rapidly growing markets of wearable electronics and the Internet of Things.

    Place, publisher, year, edition, pages
    IOP Publishing Ltd, 2021
    Keywords
    stretchable display; electrochromic display; PEDOT; PSS; screen printing; stretchable electronics
    National Category
    Textile, Rubber and Polymeric Materials
    Identifiers
    urn:nbn:se:liu:diva-182028 (URN)10.1088/2058-8585/ac3eb2 (DOI)000731759000001 ()
    Note

    Funding Agencies|Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University [SFO-Mat-LiU No. 2009-00971]

    Available from: 2022-01-03 Created: 2022-01-03 Last updated: 2023-02-03
  • 12.
    Boda, Ulrika
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. RISE Res Inst Sweden, Sweden.
    Petsagkourakis, Ioannis
    RISE Res Inst Sweden, Sweden.
    Beni, Valerio
    RISE Res Inst Sweden, Sweden.
    Ersman, Peter Andersson
    RISE Res Inst Sweden, Sweden.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fully Screen-Printed Stretchable Organic Electrochemical Transistors2023In: Advanced Materials Technologies, E-ISSN 2365-709XArticle in journal (Refereed)
    Abstract [en]

    Stretchable organic electrochemical transistors (OECTs) are promising for wearable applications within biosensing, bio-signal recording, and addressing circuitry. Efficient large-scale fabrication of OECTs can be performed with printing methods but to date there are no reports on high-performance fully printed stretchable OECTs. Herein, this challenge is addressed by developing fully screen-printed stretchable OECTs based on an architecture that minimizes electrochemical side reactions and improves long-term stability. Fabrication of the OECTs is enabled by in-house development of three stretchable functional screen-printing inks and related printing processes. The stretchable OECTs show good characteristics in terms of transfer curves, output characteristics, and transient response up to 100% static strain and 500 strain cycles at 25% and 50% strain. The strain insensitivity of the OECTs can be further improved by strain conditioning, resulting in stable performance up to 50% strain. Finally, an electrochromic smart pixel is demonstrated by connecting a stretchable OECT to a stretchable electrochromic display. It is believed that the development of screen-printed stretchable electrochemical devices, and OECTs in particular, will pave the way for their use in wearable applications and commercial products.

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  • 13. Order onlineBuy this publication >>
    Bouhafs, Chamseddine
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Structural and Electronic Properties of Graphene on 4H- and 3C-SiC2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Graphene is a one-atom-tick carbon layer arranged in a honeycomb lattice. Graphene was first experimentally demonstrated by Andre Geim and Konstantin Novoselov in 2004 using mechanical exfoliation of highly oriented pyrolytic graphite (exfoliated graphene flakes), for which they received the Nobel Prize in Physics in 2010. Exfoliated graphene flakes show outstanding electronic properties, e.g., very high free charge carrier mobility parameters and ballistic transport at room temperature. This makes graphene a suitable material for next generation radio-frequency and terahertz electronic devices. Such applications require fabrication methods of large-area graphene compatible with electronic industry. Graphene grown by sublimation on silicon carbide (SiC) offers a viable route towards production of large-area, electronic-grade material on semi-insulating substrate without the need of transfer. Despite the intense investigations in the field, uniform wafer-scale graphene with very high-quality that matches the properties of exfoliated graphene has not been achieved yet. The key point is to identify and control how the substrate affects graphene uniformity, thickness, layer stacking, structural and electronic properties. Of particular interest is to understand the effects of SiC surface polarity and polytype on graphene properties in order to achieve large-area material with tailored properties for electronic applications. The main objectives of this thesis are to address these issues by investigating the structural and electronic properties of epitaxial graphene grown on 4HSiC and 3C-SiC substrates with different surface polarities. The first part of the thesis includes a general description of the properties of graphene, bilayer graphene and graphite. Then, the properties of epitaxial graphene on SiC by sublimation are detailed. The experimental techniques used to characterize graphene are described. A summary of all papers and contribution to the field is presented at the end of Part I. Part II consists of seven papers.

    List of papers
    1. Structural properties and dielectric function of graphene grown by high-temperature sublimation on 4H-SiC(000-1)
    Open this publication in new window or tab >>Structural properties and dielectric function of graphene grown by high-temperature sublimation on 4H-SiC(000-1)
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    2015 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 117, no 8, p. 085701-Article in journal (Refereed) Published
    Abstract [en]

    Understanding and controlling growth of graphene on the carbon face (C-face) of SiC presents a significant challenge. In this work, we study the structural, vibrational, and dielectric function properties of graphene grown on the C-face of 4H-SiC by high-temperature sublimation in an argon atmosphere. The effect of growth temperature on the graphene number of layers and crystallite size is investigated and discussed in relation to graphene coverage and thickness homogeneity. An amorphous carbon layer at the interface between SiC and the graphene is identified, and its evolution with growth temperature is established. Atomic force microscopy, micro-Raman scattering spectroscopy, spectroscopic ellipsometry, and high-resolution cross-sectional transmission electron microscopy are combined to determine and correlate thickness, stacking order, dielectric function, and interface properties of graphene. The role of surface defects and growth temperature on the graphene growth mechanism and stacking is discussed, and a conclusion about the critical factors to achieve decoupled graphene layers is drawn. (C) 2015 AIP Publishing LLC.

    Place, publisher, year, edition, pages
    American Institute of Physics (AIP), 2015
    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:liu:diva-117253 (URN)10.1063/1.4908216 (DOI)000351132500070 ()
    Note

    Funding Agencies|Marie Curie actions [264613-NetFISiC]; Swedish Research Council (VR) [2011-4447, 2013-5580]; Swedish Governmental Agency for Innovation Systems (VINNOVA) under the VINNMER international qualification program [2011-03486]; Swedish foundation for strategic research (SSF) [FFL12-0181]; FP7 EU project Nano-Rf [FP7-ICT-2011-8]; French ANR under the Grafonics Project [ANR-10-NANO-0004]; European Union Seventh Framework Programme under Graphene Flagship [604391]; Knut and Alice Wallenbergs foundation

    Available from: 2015-04-22 Created: 2015-04-21 Last updated: 2023-12-28
    2. Cavity-enhanced optical Hall effect in epitaxial graphene detected at terahertz frequencies
    Open this publication in new window or tab >>Cavity-enhanced optical Hall effect in epitaxial graphene detected at terahertz frequencies
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    2017 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 421, p. 357-360Article in journal (Refereed) Published
    Abstract [en]

    Cavity-enhanced optical Hall effect at terahertz (THz) frequencies is employed to determine the free charge carrier properties in epitaxial graphene (EG) with different number of layers grown by high-temperature sublimation on 4H-SiC(0001). We find that one monolayer (ML) EG possesses p-type conductivity with a free hole concentration in the low 1012 cmᅵᅵᅵ2 range and a free hole mobility parameter as high as 1550 cm2/Vs. We also find that 6 ML EG shows n-type doping behavior with a much lower free electron mobility parameter of 470 cm2/Vs and an order of magnitude higher free electron density in the low 1013 cmᅵᅵᅵ2 range. The observed differences are discussed. The cavity-enhanced THz optical Hall effect is demonstrated to be an excellent tool for contactless access to the type of free charge carriers and their properties in two-dimensional materials such as EG.

    Place, publisher, year, edition, pages
    Elsevier, 2017
    Keywords
    THz optical Hall effect, Epitaxial graphene, Free charge carrier properties
    National Category
    Physical Sciences Condensed Matter Physics Atom and Molecular Physics and Optics Ceramics
    Identifiers
    urn:nbn:se:liu:diva-132407 (URN)10.1016/j.apsusc.2016.10.023 (DOI)000408756700015 ()
    Note

    Funding agencies: Swedish Research Council (VR) [2013-5580]; Swedish Governmental Agency for Innovation Systems (VINNOVA) under the VINNMER international qualification program [2011-03486, 2014-04712]; Swedish foundation for strategic research (SSF) [FFL12-0181, RIF14-055]

    Available from: 2016-11-09 Created: 2016-11-09 Last updated: 2023-12-28Bibliographically approved
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    Structural and Electronic Properties of Graphene on 4H- and 3C-SiC
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  • 14. Order onlineBuy this publication >>
    Cao, Danfeng
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Conducting Polymer-based Biohybrid Materials: Towards Microphysiological Chips and Soft Actuators for Bone Tissue Engineering2023Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The human body is a complex system, consisting of different types of biomolecules and living matters, such as nucleic acids, proteins, carbohydrates, lipids, serum, cells, tissues, and organs. These complex biomolecules and living matters integrate and interact dynamically to perform and maintain body functions. However, it is very difficult to study these biomaterials in vivo due to intricated relationship of biomaterials within complex body systems. Thus, researchers usually conduct an initial in-depth analysis of substances in vitro, then apply them in vivo for disease treatments or tissue repair. Recently, Hara et al. had a fantastic finding that chondrocyte-derived plasma membrane nanofragments (PMNFs) can induce bone-like tissue in vitro for only two days, while live cells or other biomaterials require at least 2-4 weeks. This effect of PMNFs is highly desirable, particularly for those elderly with osteoporosis and those with bone injuries who require rapid bone growth and repair. Recent studies have increasingly supported the notion that some non-biological materials provide important microenvironmental cues to support the activity of cells in in vitro conditions or within tissues. Based on these, living matters or biomolecules can be combined with or incorporated within specific non-biological material to create a microenvironment that further enhances cellular functions toward, for instance, combating infections and cancers or promoting tissue repair. In these cases, the materials combining biomolecules and/or living matters with non-biological materials are called biohybrid materials. Conducting polymers, e.g., polypyrrole (PPy), have become a class of promising non-biological material for the development of biohybrid materials due to their good biocompatibility, electronic/ionic conductivity, reversible volume change and switchable surface properties. Thus, in this thesis, we developed biohybrid material-based devices by the combination of PMNFs and PPy for the application in bone regeneration.  

    Firstly, as early attempts for mimicking the in vivo microenvironment to study the functions of biomolecules in vitro, bovine serum albumin (BSA) was used as a simple model of biomolecule instead of complex biomolecules. A preliminary electrophysiological chip was fabricated by immobilising BSA on the surface of PPy synthesised with polycarboxylic acid as dopant. Then the switching presentation of BSA induced by the redox state of PPy surface was further evaluated. The results showed that it is feasible to immobilise biomolecules or living matters on polycarboxylic acid doped PPy, and that the presentation of these biomolecules on PPy surface could be switched by redox potential. On the basis of the preliminary BSA electrophysiological chip, a functional electrophysiological chip with bone regeneration potential was developed by immobilising PMNFs on the PPy surface. Despite the large size of the PMNFs, the results demonstrated that the PMNFs could be successfully immobilised on the PPy surface, and that the presentation of PMNFs could also be modified by changing the redox state of the PPy surface. Moreover, the incubation of the PMNFs-based chips in mineralisation medium resulted in the formation of minerals, and the morphological structures of the minerals were different under the stimulation of redox potential. Furthermore, the different microstructural morphologies of the formed minerals can modulate the osteogenic differentiation of mesenchymal stem cells (MSCs).   

    Secondly, based on the surface mineralisation study on the above electrophysiological chip at a two-dimensional (2D) scale, soft and biohybrid actuators based on PMNF-PPy biohybrid material were further developed for the deeper exploration of the bone regeneration at a three-dimensional (3D) scale. This is facilitated by the actuation of the soft and biohybrid actuator, which can achieve complex motions with on-demand geometry and actuation modalities in 3D. Therefore, a double layer of free-standing soft actuator was fabricated by combining PDMS passive layer and PPy active layer, while PMNFs were either immobilised on the PPy surface or doped into the PPy film. The actuation of PDMS/PPy-PMNF actuators proved that the mineralisation of PMNFs could increase the stiffness of the actuator and decrease the movement of actuator to some extent, although this reduction of movement was not significant. The results indicate that the mineralisation of PMNFs possesses a variable stiffness effect in soft actuators.   

    Next, an alginate gel (Alg)-PPy actuator was developed in order to achieve an actuator that is more sensitive to variable stiffness change and that performs more distinguished movement changes. In this experiment, PMNFs were incorporated into the alginate gel. The alginate gel functionalised with PMNFs facilitated the formation of a thick mineral layer, which almost completely suppressed the actuator movement. Finally, the patterned Alg-PPy actuator was smartly morphing on the bone for mineralisation. Excitingly, the mineralised actuator was integrated into the bone, demonstrating the potential application of PMNF-PPy biohybrid materials for bone regeneration. 

    List of papers
    1. Biohybrid Variable-Stiffness Soft Actuators that Self-Create Bone
    Open this publication in new window or tab >>Biohybrid Variable-Stiffness Soft Actuators that Self-Create Bone
    2022 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 34, no 8, article id 2107345Article in journal (Refereed) Published
    Abstract [en]

    Inspired by the dynamic process of initial bone development, in which a soft tissue turns into a solid load-bearing structure, the fabrication, optimization, and characterization of bioinduced variable-stiffness actuators that can morph in various shapes and change their properties from soft to rigid are hereby presented. Bilayer devices are prepared by combining the electromechanically active properties of polypyrrole with the compliant behavior of alginate gels that are uniquely functionalized with cell-derived plasma membrane nanofragments (PMNFs), previously shown to mineralize within 2 days, which promotes the mineralization in the gel layer to achieve the soft to stiff change by growing their own bone. The mineralized actuator shows an evident frozen state compared to the movement before mineralization. Next, patterned devices show programmed directional and fixated morphing. These variable-stiffness devices can wrap around and, after the PMNF-induced mineralization in and on the gel layer, adhere and integrate onto bone tissue. The developed biohybrid variable-stiffness actuators can be used in soft (micro-)robotics and as potential tools for bone repair or bone tissue engineering.

    Place, publisher, year, edition, pages
    Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2022
    Keywords
    actuators, biohybrids, mineralization, variable stiffness
    National Category
    Physical Chemistry
    Identifiers
    urn:nbn:se:liu:diva-182493 (URN)10.1002/adma.202107345 (DOI)000743102000001 ()34877728 (PubMedID)2-s2.0-85122837081 (Scopus ID)
    Note

    Funding Agencies: Japanese Society of the Promotion of Science (JSPS) Bridge Fellowship program [BR170502]; KAKENHI Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research (KAKENHI) [JP20H04534]; Swedish Research Council European Commission [VR2014-3079]; Promobilia [F17603]; China Scholarship Council [201808330454]; JSPS Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science [JPJSBP 120 209 923]; STINT, The Swedish Foundation for International Cooperation in Research and Higher Education [MG2019-8171]

    Available from: 2022-01-26 Created: 2022-01-26 Last updated: 2023-03-16Bibliographically approved
    2. Soft actuators that self-create bone for biohybrid (micro)robotics
    Open this publication in new window or tab >>Soft actuators that self-create bone for biohybrid (micro)robotics
    2022 (English)In: Proceedings of The 5th International Conference on Manipulation, Automation, And Robotics at Small Scales (MARSS 2022), Institute of Electrical and Electronics Engineers (IEEE), 2022, p. 1-6Conference paper, Published paper (Refereed)
    Abstract [en]

    Here we present a new class of variable stiffness actuators for soft robotics based on biohybrid materials that change their state from soft-to-hard by creating their own bones. The biohybrid variable stiffness soft actuators were fabricated by combining the electromechanically active polymer polypyrrole (PPy) with a soft substrate of polydimethylsiloxane or alginate gel. These actuators were functionalized with cell-derived plasma membrane nanofragments (PMNFs), which promote rapid mineralization within 2 days. These actuators were used in robotic devices, and PMNF mineralization resulted in the robotic devices to achieve a soft to stiff state change and thereby a decreased or stopped actuation. Moreover, perpendicularly and diagonally patterned actuators were prepared. The patterned actuators showed programmed directional actuation motion and could be fixated in this programmed state. Finally, patterned actuators that combined soft and rigid parts in one actuator showed more complex actuation motion. Together, these variable stiffness actuators could expand the range of applications of morphing robotics with more complex structures and functions. 

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2022
    National Category
    Physical Chemistry
    Identifiers
    urn:nbn:se:liu:diva-187834 (URN)10.1109/MARSS55884.2022.9870251 (DOI)000864658200005 ()9781665459730 (ISBN)9781665459747 (ISBN)
    Conference
    5th International Conference on Manipulation, Automation, and Robotics at Small Scales (MARSS), Toronto, CANADA, jul 25-29, 2022
    Note

    Funding: Japanese Society of the Promotion of Science (JSPS) Bridge Fellowship program [BR170502]; KAKENHI [JP20H04534]; JSPS [JPJSBP 120 209 923]; STINT; Swedish Research Council [VR2014-3079]; China Scholarship Council [201808330454]

    Available from: 2022-08-26 Created: 2022-08-26 Last updated: 2023-10-12Bibliographically approved
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  • 15.
    Cao, Danfeng
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez Gil, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Hara, Emilio Satoshi
    Okayama Univ, Japan.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Variable Stiffness Actuators with Covalently Attached Nanofragments that Induce Mineralization2023In: Advanced Materials Technologies, E-ISSN 2365-709XArticle in journal (Refereed)
    Abstract [en]

    Soft robotics has attracted great attention owing to their immense potential especially in human-robot interfaces. However, the compliant property of soft robotics alone, without stiff elements, restricts their applications under load-bearing conditions. Here, biohybrid soft actuators, that create their own bone-like rigid layer and thus alter their stiffness from soft to hard, are designed. Fabrication of the actuators is based on polydimethylsiloxane (PDMS) with an Au film to make a soft substrate onto which polypyrrole (PPy) doped with poly(4-styrenesulfonic-co-maleic acid) sodium salt (PSA) is electropolymerized. The PDMS/Au/PPy(PSA) actuator is then functionalized, chemically and physically, with plasma membrane nanofragments (PMNFs) that induce bone formation within 3 days, without using cells. The resulting stiffness change decreased the actuator displacement; yet a thin stiff layer couldnot completely stop the actuators movement, while a relatively thick segment could, but resulted in partial delamination the actuator. To overcome the delamination, an additional rough Au layer was electroplated to improve the adhesion of the PPy onto the substrate. Finally, an alginate gel functionalized with PMNFs was used to create a thicker mineral layer mimicking the collagen-apatite bone structure, which completely suppressed the actuator movement without causing any structural damage.

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  • 16. Order onlineBuy this publication >>
    Delavari, Najmeh
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Computational Modelling of Organic Bioelectronic Devices and Materials2022Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Bioelectronics being the intersection field between electronics and biology, aims to investigate the transduction between electronic signals and ionic signals within a biological environment. Organic materials such as conducting polymers are extensively utilized in the fabrication and development of bioelectronic devices due to their ability to conduct both electrons and ions. In addition, organic materials offer advantages compared to their inorganic traditional counterparts, including being flexible, solution processable and printable as it is an easy strategy for the fabrication process. These unique properties make organic conductor materials a good match for a wide range of organic bioelectronic applications such as organic transistors and biosensors interacting with biological/physiological systems and pave the way for more developments in the in the state-of-the-art technology of organic bioelectronics. Many of the organic bioelectronic devices function in contact with a biological system, usually an electrolytic medium, where mostly ionic transport occurs. Therefore, understanding the structural, morphological, and electronic properties of materials and devices used for organic bioelectronics applications is the topic of strong current interest.  

    This thesis is focused on two levels of computational investigations: studying bioelectronic devices and studying materials used for bioelectronic applications. The former includes modelling of electrolyte-gated organic field effect transistors (EGOFET), whereas the latter provides theoretical insights into morphological changes, ion injection, water intake, and self-assembly of conducting polymers. In the part of the thesis addressing the device modelling we first proposed an EGOFET model based on the Nernst-Planck-Poisson equations to describe, on equal footing, both the polymer and the electrolyte regions within the device. Using the developed model, we modelled and analysed experimentally measured current–voltage characteristics of the device (the output and transfer curves), where a semi-qualitative agreement between the experimental and calculated results was achieved. In a follow-up study, we demonstrated that Nernst-Planck-Poisson modelling represents a powerful tool allowing quantitative device design, modelling and analysis enabling us to forecast the influence of geometrical parameters as well as the materials used as electrolyte and the organic semiconductor for the case of a printed EGOFET.  

    To explore the ion exchange phenomena at the interface of conducting polymers with aqueous electrolytes, we provided a detailed atomistic understanding of the water intake, swelling, and ion injection during cyclic voltammetry. By combining the molecular dynamics simulations with experimental measurements such as e-QCM (electrochemical quartz crystal microbalance), UV−VIS−NIR absorption spectroscopy, and XPS (X-ray photoelectron spectroscopy) we demonstrated that the PEDOT:Tos film underwent significant changes in morphology and mass during the redox processes. Finally, we studied the self-assembly of polythiophene based polymers with glycol and alkyl side chains deposited on the gold surface. Using molecular dynamics simulations, we investigated the diffusion of the molecules and analysed their conformations.  We explored how different side chains interact with each other and how they influence the conjugated polymers self-assembly.  

    We believe that the knowledge we acquired from our studies, combining experimental investigations with computational insights, provided an important understanding of the fundamental molecular processes at the material and device level that could help a practical enhancement in the field of organic bioelectronics.

    List of papers
    1. Nernst-Planck-Poisson analysis of electrolyte-gated organic field-effect transistors
    Open this publication in new window or tab >>Nernst-Planck-Poisson analysis of electrolyte-gated organic field-effect transistors
    Show others...
    2021 (English)In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 54, no 41, article id 415101Article in journal (Refereed) Published
    Abstract [en]

    Electrolyte-gated organic field-effect transistors (EGOFETs) represent a class of organic thin-film transistors suited for sensing and biosensing in aqueous media, often at physiological conditions. The EGOFET device includes electrodes and an organic semiconductor channel in direct contact with an electrolyte. Upon operation, electric double layers are formed along the gate-electrolyte and the channel-electrolyte interfaces, but ions do not penetrate the channel. This mode of operation allows the EGOFET devices to run at low voltages and at a speed corresponding to the rate of forming electric double layers. Currently, there is a lack of a detailed quantitative model of the EGOFETs that can predict device performance based on geometry and material parameters. In the present paper, for the first time, an EGOFET model is proposed utilizing the Nernst-Planck-Poisson equations to describe, on equal footing, both the polymer and the electrolyte regions of the device configuration. The generated calculations exhibit semi-qualitative agreement with experimentally measured output and transfer curves.

    Place, publisher, year, edition, pages
    IOP PUBLISHING LTD, 2021
    Keywords
    Nernst-Planck-Poisson equations; electrolyte-gated organic field-effect transistors (EGOFET); organic electronics; device modelling
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-178266 (URN)10.1088/1361-6463/ac14f3 (DOI)000679083200001 ()
    Note

    Funding Agencies|Swedish Research CouncilSwedish Research CouncilEuropean Commission [2017-04474]; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; French National Research Agency (Agence Nationale de la Recherche) through the project EGOFLEXFrench National Research Agency (ANR) [ANR-17-CE08-0025]

    Available from: 2021-08-18 Created: 2021-08-18 Last updated: 2022-04-27
    2. Water Intake and Ion Exchange in PEDOT:Tos Films upon Cyclic Voltammetry: Experimental and Molecular Dynamics Investigation
    Open this publication in new window or tab >>Water Intake and Ion Exchange in PEDOT:Tos Films upon Cyclic Voltammetry: Experimental and Molecular Dynamics Investigation
    Show others...
    2021 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 54, no 13, p. 6552-6562Article in journal (Refereed) Published
    Abstract [en]

    Conductive polymer PEDOT:Tos (3,4-ethylenedioxythiophene doped with molecular tosylate) gained considerable attention in various devices for bioelectronic applications, such as organic transistors and sensors. Many of these devices function upon oxidation/reduction processes in contact with aqueous electrolytes. So far, theoretical insight into morphological changes, ion injection, and water intake during these processes was rather limited. In the present work, we combined experiments and molecular dynamics simulations to study the water intake, swelling, and exchange of ions in the PEDOT:Tos film during cyclic voltammetry. We showed that the film underwent significant changes in morphology and mass during the redox processes. We observed both experimentally and in simulations that the film lost its mass during reduction, as tosylate and Na were expelled and gained mass during oxidation mainly due to the uptake of anions, i.e., tosylate and Cl. The results were in line with the UV-VIS-NIR absorption measurements and X-ray photoelectron spectroscopy (XPS) measurements, which revealed that during the redox process a portion of Tos was replaced by Cl- as the counterion for PEDOT. Also, the relative mass change between the most oxidized and reduced states was similar to 10 to 14% according to both experiments and simulations. We detected an overall material loss of the film during voltammetry cycles indicating that a portion of the material leaving the film during reduction did not return to the film during the consecutive oxidation. Our combined experimental/simulation study unraveled the underlying molecular processes in the PEDOT:Tos film upon the redox process, providing the essential understanding needed to improve and assess the performance of bioelectronic devices.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2021
    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:liu:diva-178503 (URN)10.1021/acs.macromol.1c00723 (DOI)000674278700061 ()
    Note

    Funding Agencies|Swedish Research CouncilSwedish Research CouncilEuropean Commission [2016-05990, 2017-04474]; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; Swedish e-Science Research Centre (SeRC)

    Available from: 2021-08-25 Created: 2021-08-25 Last updated: 2022-04-27
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  • 17.
    Demchyshyn, Stepan
    et al.
    Johannes Kepler University of Linz, Austria; Johannes Kepler University of Linz, Austria; LIT, Austria.
    Melanie Roemer, Janina
    Ludwig Maximilians University of Munchen, Germany; Ludwig Maximilians University of Munchen, Germany.
    Groiss, Heiko
    Johannes Kepler University of Linz, Austria; Johannes Kepler University of Linz, Austria.
    Heilbrunner, Herwig
    Johannes Kepler University of Linz, Austria.
    Ulbricht, Christoph
    Johannes Kepler University of Linz, Austria; Johannes Kepler University of Linz, Austria.
    Apaydin, Dogukan
    Johannes Kepler University of Linz, Austria.
    Boehm, Anton
    Ludwig Maximilians University of Munchen, Germany; Ludwig Maximilians University of Munchen, Germany.
    Ruett, Uta
    DESY, Germany.
    Bertram, Florian
    DESY, Germany.
    Hesser, Guenter
    Johannes Kepler University of Linz, Austria.
    Clark Scharber, Markus
    Johannes Kepler University of Linz, Austria.
    Serdar Sariciftci, Niyazi
    Johannes Kepler University of Linz, Austria.
    Nickel, Bert
    Ludwig Maximilians University of Munchen, Germany; Ludwig Maximilians University of Munchen, Germany; Nanosyst Initiat Munich, Germany.
    Bauer, Siegfried
    Johannes Kepler University of Linz, Austria.
    Glowacki, Eric
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Kaltenbrunner, Martin
    Johannes Kepler University of Linz, Austria; LIT, Austria.
    Confining metal-halide perovskites in nanoporous thin films2017In: Science Advances, E-ISSN 2375-2548, Vol. 3, no 8, article id e1700738Article in journal (Refereed)
    Abstract [en]

    Controlling the size and shape of semiconducting nanocrystals advances nanoelectronics and photonics. Quantumconfined, inexpensive, solution-derived metal halide perovskites offer narrowband, color-pure emitters as integral parts of next-generation displays and optoelectronic devices. We use nanoporous silicon and alumina thin films as templates for the growth of perovskite nanocrystallites directly within device-relevant architectures without the use of colloidal stabilization. We find significantly blue-shifted photoluminescence emission by reducing the pore size; normally infrared-emitting materials become visibly red, and green-emitting materials become cyan and blue. Confining perovskite nanocrystals within porous oxide thin films drastically increases photoluminescence stability because the templates auspiciously serve as encapsulation. We quantify the template-induced size of the perovskite crystals in nanoporous silicon with microfocus high-energy x-ray depth profiling in transmission geometry, verifying the growth of perovskite nanocrystals throughout the entire thickness of the nanoporous films. Low-voltage electroluminescent diodes with narrow, blue-shifted emission fabricated from nanocrystalline perovskites grown in embedded nanoporous alumina thin films substantiate our general concept for next-generation photonic devices.

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  • 18.
    Du, Yong
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. Shanghai Inst Technol, Peoples R China.
    Xu, Jiayue
    Shanghai Inst Technol, Peoples R China.
    Paul, Biplab
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Flexible thermoelectric materials and devices2018In: APPLIED MATERIALS TODAY, ISSN 2352-9407, Vol. 12, p. 366-388Article, review/survey (Refereed)
    Abstract [en]

    Thermoelectric generators (TEGs) can directly convert waste heat into electrical power. In the last few decades, most research on thermoelectrics has focused on inorganic bulk thermoelectric materials and corresponding devices, and their thermoelectric properties have been significantly improved. An emerging topic is flexible devices, where the use of bulk inorganic materials is precluded by their inherent rigidity. The purpose of this paper is to review the research progress on flexible thermoelectric materials and generators, including theoretical principles for TEGs, conducting polymer TE materials, nanocomposites comprised of inorganic nanostructures in polymer matrices and fully inorganic flexible TE materials in nanostructured thin films. Approaches for flexible TEGs and components are reviewed, and remaining challenges discussed. (C) 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

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  • 19.
    Dutta, Sujan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Mehraeen, Shayan
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Persson, Nils-Krister
    The Swedish School of Textiles, Polymeric E-textiles, University of Borås, Borås, Sweden.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    The effect of electroactive length and intrinsic conductivity on the actuation behaviour of conducting polymer-based yarn actuators for textile muscles2022In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 370, article id 132384Article in journal (Refereed)
    Abstract [en]

    Recently, electrically driven conducting polymer (CP) coated yarns have shown great promise to develop soft wearable applications because of their electrical and mechanical behaviour. However, designing a suitable yarn actuator for textile-based wearables with high strain is challenging. One reason for the low strain is the voltage drop along the yarn, which results in only a part of the yarn being active. To understand the voltage drop mechanism and overcome this issue intrinsically conductive yarns were used to create a highly conductive path along the full length of the yarn actuator. Ag plated knit-de-knit (Ag-KDK) structured polyamide yarns were used as the intrinsically conductive core material of the CP yarn actuators and compared with CP yarn actuators made of a non-conductive core knit-de-knit (KDK) yarn. The CP yarn actuators were fabricated by coating the core yarns with poly(3,4-ethylene dioxythiophene): poly(styrene sulfonic acid) followed by electrochemical polymerization of polypyrrole. Furthermore, to elucidate the effect of the capillarity of the electrolyte through the yarn actuator, two different approaches to electrochemical actuation were applied. All actuating performance of the materials were investigated and quantified in terms of both isotonic displacement and isometric developed forces. The resultant electroactive yarn exhibits high strain (0.64 %) in NaDBS electrolytes as compared to previous CP yarn actuator. The actuation and the electroactivity of the yarn were retained up to 100 cycles. The new highly conductive yarns will shed light on the development of next-generation textile-based exoskeleton suits, assistive devices, wearables, and haptics garments.

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  • 20.
    Erdtman, Edvin
    et al.
    Akademin för textil, teknik och ekonomi, Högskolan i Borås, Borås, Sverige.
    Bohlén, Martin
    Akademin för textil, teknik och ekonomi, Högskolan i Borås, Borås, Sverige.
    Ahlström, Peter
    Akademin för textil, teknik och ekonomi, Högskolan i Borås, Borås, Sverige.
    Gkourmpis, Thomas
    Innovation & Technology, Borealis AB, Stenungsund, Sweden.
    Berlin, Mikael
    Tetra Pak Packaging Solutions AB, Ruben Rausings Gata, Lund, Sweden.
    Andersson, Thorbjörn
    Tetra Pak Packaging Solutions AB, Ruben Rausings Gata, Lund, Sweden.
    Bolton, Kim
    Akademin för textil, teknik och ekonomi, Högskolan i Borås, Borås, Sverige.
    A molecular-level computational study of the diffusion and solubility of water and oxygen in carbonaceous polyethylene nanocomposites2016In: Journal of Polymer Science Part B: Polymer Physics, ISSN 0887-6266, E-ISSN 1099-0488, Vol. 54, no 5, p. 589-602Article in journal (Refereed)
    Abstract [en]

    Monte Carlo and molecular dynamics simulations were performed to investigate the effect on the solubility, diffusion, and permeability of water and oxygen when adding graphene or single-walled carbon nanotubes (SWCNTs) to polyethylene (PE). When compared with pure PE, addition of graphene lowered the solubility of water, whereas at lower temperatures, the oxygen solubility increased because of the oxygen–graphene interaction. Addition of SWCNTs lowered the solubility of both water and oxygen when compared with pure PE. A detailed analysis showed that an ordered structure of PE is induced near the additive surface, which leads to a decrease in the diffusion coefficient of both penetrants in this region. The addition of graphene does not change the permeation coefficient of oxygen (in the direction parallel to the filler) and, in fact, may even increase this coefficient when compared with pure PE. In contrast, the water permeability is decreased when graphene is added to PE. The addition of SWCNTs decreases the permeability of both penetrants. Graphene can consequently be added to selectively increase the solubility and permeation of oxygen over water, at least at lower temperatures. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 589–602

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  • 21.
    Fabiano, Simone
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Abdollahi Sani, Negar
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering. RISE Acreo, Sweden.
    Kawahara, Jun
    RISE Acreo, Sweden; LINTEC Corp, Japan.
    Kergoat, Loig
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering. Aix Marseille University, France.
    Nissa, Josefin
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Engquist, Isak
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Ferroelectric polarization induces electronic nonlinearity in ion-doped conducting polymers2017In: Science Advances, E-ISSN 2375-2548, Vol. 3, no 6, article id e1700345Article in journal (Refereed)
    Abstract [en]

    Poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is an organic mixed ion-electron conducting polymer. The PEDOT phase transports holes and is redox-active, whereas the PSS phase transports ions. When PEDOT is redox-switched between its semiconducting and conducting state, the electronic and optical properties of its bulk are controlled. Therefore, it is appealing to use this transition in electrochemical devices and to integrate those into large-scale circuits, such as display or memory matrices. Addressability and memory functionality of individual devices, within these matrices, are typically achieved by nonlinear current-voltage characteristics and bistability-functions that can potentially be offered by the semiconductor-conductor transition of redox polymers. However, low conductivity of the semiconducting state and poor bistability, due to self-discharge, make fast operation and memory retention impossible. We report that a ferroelectric polymer layer, coated along the counter electrode, can control the redox state of PEDOT. The polarization switching characteristics of the ferroelectric polymer, which take place as the coercive field is overcome, introduce desired nonlinearity and bistability in devices that maintain PEDOT in its highly conducting and fast-operating regime. Memory functionality and addressability are demonstrated in ferro-electrochromic display pixels and ferro-electrochemical transistors.

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  • 22.
    Fabiano, Simone
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Facchetti, Antonio
    Northwestern Univ, IL USA; Northwestern Univ, IL USA; Flexterra Inc, IL USA.
    Stretchable helix-structured fibre electronics2021In: NATURE ELECTRONICS, ISSN 2520-1131, Vol. 4, p. 864-865Article in journal (Other academic)
    Abstract [en]

    Printed thin-film transistors and circuits fabricated on plastic strips can be wrapped around fibres to create stretchable electronics.

  • 23.
    Falk, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Patterning of Highly Conductive Conjugated Polymers for Actuator Fabrication2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Trilayer polypyrrole microactuators that can operate in air have previously been developed. They consist of two outer layers ofthe electroactive polymer polypyrrole (PPy) and one inner layer of a porous poly(vinylidene flouride) (PVDF) membranecontaining a liquid electrolyte. The two outer layers of PPy are each connected with gold electrodes and separated by the porousPVDF membrane. This microtool is fabricated by bottom-up microfabrication However, porous PVDF layer is not compatible with bottom upmicrofabrication and highly swollen SPE suffers from gold electrode delamination. Hence, in this MSc project/thesis a novelmethod of flexible electrode fabrication with conducting polymers was developed by soft lithography and drop-on-demandprinting. The gold electrodes were replaced by patterned vapor phase polymerized (VPP) poly(3,4-ethylenedioxythiophene) (PEDOT)electrodes due to its high electrical conductivity and versatile process ability. The replacement of the stiff gold electrodes byflexible and stretchable PEDOT allowed high volume change of the material and motions. The PEDOT electrodes werefabricated by patterning the oxidant iron tosylate using microcontact printing and drop-on-demand printing. Moreover, thePVDF membrane has been replaced by a nitrile butadiene rubber/poly(ethylene oxide) semi-interpenetrating polymer network(IPN) to increase ion conductivity and strechability and hence actuator performance.

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  • 24.
    Felekidis, Nikolaos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Melianas, Armantas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Stanford University, CA 94305 USA.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Design Rule for Improved Open-Circuit Voltage in Binary and Ternary Organic Solar Cells2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 42, p. 37070-37077Article in journal (Refereed)
    Abstract [en]

    Mixing different compounds to improve functionality is one of the pillars of the organic electronics field. Here, the degree to which the charge transport properties of the constituent materials are simply additive when materials are mixed is quantified. It is demonstrated that in bulk heterojunction organic solar cells, hole mobility in the donor phase depends critically on the choice of the acceptor material, which may alter the energetic disorder of the donor. The same holds for electron mobility and disorder in the acceptor. The associated mobility differences can exceed an order of magnitude compared to pristine materials. Quantifying these effects by a state-filling model for the open-circuit voltage (V-oc) of ternary Donor:Acceptor(l):Acceptor(2) (D:A(1):A(2)) organic solar cells leads to a physically transparent description of the surprising, nearly linear tunability of the Voc with the A(1):A(2) weight ratio. It is predicted that in binary OPV systems, suitably chosen donor and acceptor materials can improve the device power conversion efficiency (PCE) by several percentage points, for example from 11 to 13.5% for a hypothetical state-ofthe-art organic solar cell, highlighting the importance of this design rule.

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  • 25. Ganesan, Manikandan
    et al.
    Mehraeen, Shayan
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Persson, Nils-Krister
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Rapid responsive behaviour of electro-chemically driven coiled yarn actuators2023Conference paper (Other academic)
  • 26.
    Gelmi, Amy
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Rafat, Mehrdad
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, Faculty of Medicine and Health Sciences.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Actuating electroactive scaffolds for cardiac tissue regeneration2014Conference paper (Refereed)
  • 27.
    Ghosh, Sarbani
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Effect of Substrate on Structural Phase Transition in a Conducting Polymer during Ion Injection and Water Intake: A View from a Computational Microscope2020In: ACS APPLIED ELECTRONIC MATERIALS, ISSN 2637-6113, Vol. 2, no 12, p. 4034-4041Article in journal (Refereed)
    Abstract [en]

    Conducting polymers operating in aqueous electrolyte represent mixed electron-ion conductors, where the ion injection and water intake can lead to structural and morphological changes that can strongly affect the material morphology and device performance. In the present paper, using molecular dynamics simulations, we provide an atomistic understanding of the structural phase transitions during electrochemical oxidation and ion injection in a conjugated polymer with glycolated side chains recently reported by Bischak et al. [J. Am. Chem. Soc., 2020, 142, 7434], where the polymer switched between two structurally distinct phases corresponding to different oxidation levels. To outline the structural changes, we calculated the polymer film morphology and X-ray diffraction patterns at different oxidation levels. We demonstrated that the observed phase transition arises due to interplay between several factors, including the effect of the substrate leading to the preferential edge-on arrangement of the chains and formation of lamellas; unzipping of the interdigitated polymer chains during oxidation and ion intake; and changes in the morphology when pi-pi stacking is absent at low oxidation level and forms at the high oxidation level facilitating the electron mobility and enabling the oxidation of the polymer film. Our calculations quantitatively reproduce the experimental data, which outlines the predictive power of the molecular modeling of the polymer systems that can be utilized for the design of materials and devices with improved performance.

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  • 28.
    Gladisch, Johannes
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Stavrinidou, Eleni
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ghosh, Sarbani
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Giovannitti, Alexander
    Imperial Coll London, England.
    Moser, Maximilian
    Imperial Coll London, England.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    McCulloch, Iain
    Imperial Coll London, England; KAUST, Saudi Arabia.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Reversible Electronic Solid-Gel Switching of a Conjugated Polymer2020In: ADVANCED SCIENCE, ISSN 2198-3844, Vol. 7, no 2, article id 1901144Article in journal (Refereed)
    Abstract [en]

    Conjugated polymers exhibit electrically driven volume changes when included in electrochemical devices via the exchange of ions and solvent. So far, this volumetric change is limited to 40% and 100% for reversible and irreversible systems, respectively, thus restricting potential applications of this technology. A conjugated polymer that reversibly expands by about 300% upon addressing, relative to its previous contracted state, while the first irreversible actuation can achieve values ranging from 1000-10 000%, depending on the voltage applied is reported. From experimental and theoretical studies, it is found that this large and reversible volumetric switching is due to reorganization of the polymer during swelling as it transforms between a solid-state phase and a gel, while maintaining percolation for conductivity. The polymer is utilized as an electroactive cladding to reduce the void sizes of a porous carbon filter electrode by 85%.

  • 29.
    Glowacki, Eric
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Warsaw Univ Technol, Poland.
    Stavrinidou, Eleni
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Khodagholy, Dion
    Columbia Univ, NY 10027 USA.
    Bioelectronics Research Reaches New Heights2020In: Advanced Materials Technologies, E-ISSN 2365-709X, Vol. 5, no 3, article id 2000106Article in journal (Other academic)
    Abstract [en]

    n/a

  • 30.
    Golabi, Mohsen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Modulated Smart Material Surfaces for Bacterial Differentiation.2015In: Sweden-Japan Seminar on Nanomaterials and Nanotechnology – SJS-Nano, Linköping, Sweden, 10-11 March 2015., Japan Society for the Promotion of Science (JSPS), Stockholm. , 2015, p. 30-Conference paper (Refereed)
    Abstract [en]

    A novel rapid method for bacterial differentiation is explored based on the specific adhesion pattern of bacterial strains to tunable polymer surfaces. These preliminary investigations lay the foundation for the development of an electronically tunable array of sensors that will provide patterns of information that feed into computational recognition algorithms to enable swift diffentiation of bacterial species. Different types of counter ions were used to electrochemically fabricate dissimilar polypyrrole (PPy) films with diverse physicochemical properties such as hydrophobicity, thickness and roughness. These were then modulated into three different oxidation states in each case.  The dissimilar sets of conducting polymers were exposed to a number of different bacterial strains. Generally, the number of cells of a particular bacterial strain that adhered varied when exposed to dissimilar polymer surfaces, due to the effects of the surface properties of the polymer on bacterial attachment. Similarly, the number of cells that adhered varied with different bacterial strains exposed to the same surface, reflecting the different surface properties of the bacteria. Five different bacterial strains, Deinococcus proteolyticus, Serratia marcescens, Pseudomonas fluorescens, Alcaligenes faecalis and Staphylococcus epidermidis, were seeded onto various PPy surfaces. By analysis of the fluorescent microscope images, the number of bacterial cell adhered to each surface were evaluated. Principal Component Analysis showed that all had their own specific adhesion pattern with respect to the set of applied PPy areas.  Hence, these strains could be discriminated by this simple, label-free method. In summary, this provides a proof-of-concept for using specific adhesion properties of bacterial strains in conjunction with tunable polymer arrays and pattern recognition as a method for rapid bacterial identification in situ.

  • 31. Golabi, Mohsen
    et al.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Tunable Conjugated Polymers for Bacterial Differentiation2015In: 4th International Conference on Bio-Sensing Technology, 10-13 May 2015, Lisbon, Portugal., Elsevier, 2015Conference paper (Refereed)
    Abstract [en]

    A novel rapid method for bacterial differentiation is explored based on the specific adhesion pattern of bacteria to tunable polymer surfaces. Different types of counter ions were used to electrochemically fabricate dissimilar polypyrrole (PPy) films with diverse physicochemical properties such as hydrophobicity, thickness and roughness. In order to expand the number of individual sensors in the array, three different redox states (as fabricated, oxidised and reduced) of each PPy film were also employed. These dissimilar PPy surfaces were exposed to five different bacteria, Deinococcus proteolyticus, Staphylococcus epidermidis, Alcaligenes faecalis, Pseudomonas fluorescens and Serratia marcescens, , which were seeded onto the various PPy surfaces. Fluorescent microscope images were taken and used to quantify the number of cells adhering to the surfaces.  Generally, the number of cells of a particular bacterial strain that adhered varied when exposed to dissimilar polymer surfaces, due to the effects of the surface properties of the polymer on bacterial attachment. Similarly, the number of cells that adhered varied with different bacteria exposed to the same surface, reflecting the different surface properties of the bacteria. Statistical analysis and principal component analysis showed that all had their own specific adhesion pattern with respect to the array of PPy surfaces. Hence, these bacteria could be discriminated by this simple label-free method. In summary, this provides a proof-of-concept for using specific adhesion properties of bacterial in conjunction with tunable polymer arrays and pattern recognition as a method for rapid bacterial identification in situ.

  • 32.
    Golabi, Mohsen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Tunable conjugated polymers for bacterial differentiation2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 222, p. 839-848Article in journal (Refereed)
    Abstract [en]

    A novel rapid method for bacterial differentiation is explored based on the specific adhesion pattern of bacterial strains to tunable polymer surfaces. Different types of counter ions were used to electrochemically fabricate dissimilar polypyrrole (PPy) films with diverse physicochemical properties such as hydrophobicity, thickness and roughness. These were then modulated into three different oxidation states in each case. The dissimilar sets of conducting polymers were exposed to five different bacterial strains, Deinococcus proteolyticus, Serratia marcescens, Pseudomonas fluorescens, Alcaligenes faecalis and Staphylococcus epidermidis. By analysis of the fluorescent microscope images, the number of bacterial cells adhered to each surface were evaluated. Generally, the number of cells of a particular bacterial strain that adhered varied when exposed to dissimilar polymer surfaces, due to the effects of the surface properties of the polymer on bacterial attachment. Similarly, the number of cells that adhered varied with different bacterial strains exposed to the same surface, reflecting the different surface properties of the bacteria. Principal component analysis showed that each strain of bacteria had its own specific adhesion pattern. Hence, they could be discriminated by this simple, label-free method based on tunable polymer arrays combined with pattern recognition. (C) 2015 Elsevier B.V. All rights reserved.

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  • 33.
    Goodall, Rhys E. A.
    et al.
    Univ Cambridge, England.
    Parackal, Abhijith S
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Faber, Felix A.
    Univ Cambridge, England.
    Armiento, Rickard
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Lee, Alpha A.
    Univ Cambridge, England.
    Rapid discovery of stable materials by coordinate-free coarse graining2022In: Science Advances, E-ISSN 2375-2548, Vol. 8, no 30, article id eabn4117Article in journal (Refereed)
    Abstract [en]

    A fundamental challenge in materials science pertains to elucidating the relationship between stoichiometry, stability, structure, and property. Recent advances have shown that machine learning can be used to learn such relationships, allowing the stability and functional properties of materials to be accurately predicted. However, most of these approaches use atomic coordinates as input and are thus bottlenecked by crystal structure identification when investigating previously unidentified materials. Our approach solves this bottleneck by coarse-graining the infinite search space of atomic coordinates into a combinatorially enumerable search space. The key idea is to use Wyckoff representations, coordinate-free sets of symmetry-related positions in a crystal, as the input to a machine learning model. Our model demonstrates exceptionally high precision in finding unknown theoretically stable materials, identifying 1569 materials that lie below the known convex hull of previously calculated materials from just 5675 ab initio calculations. Our approach opens up fundamental advances in computational materials discovery.

  • 34.
    Gorbunov, Andrey V.
    et al.
    Eindhoven Univ Technol, Netherlands.
    Iglesias, Miguel Garcia
    Eindhoven Univ Technol, Netherlands.
    Guilleme, Julia
    Univ Autonoma Madrid, Spain.
    Cornelissen, Tim
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Roelofs, W. S. Christian
    Eindhoven Univ Technol, Netherlands.
    Torres, Tomas
    Univ Autonoma Madrid, Spain; IM DEA Nanociencia, Spain.
    Gonzalez-Rodriguez, David
    Univ Autonoma Madrid, Spain.
    Meijer, E. W.
    Eindhoven Univ Technol, Netherlands.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering. Eindhoven Univ Technol, Netherlands.
    Ferroelectric self-assembled molecular materials showing both rectifying and switchable conductivity2017In: Science Advances, E-ISSN 2375-2548, Vol. 3, no 9, article id e1701017Article in journal (Refereed)
    Abstract [en]

    Advanced molecular materials that combine two or more physical properties are typically constructed by combining different molecules, each being responsible for one of the properties required. Ideally, single molecules could take care of this combined functionality, provided they are self-assembled correctly and endowed with different functional subunits whose strong electronic coupling may lead to the emergence of unprecedented and exciting properties. We present a class of disc-like semiconducting organic molecules that are functionalized with strong dipolar side groups. Supramolecular organization of these materials provides long-range polar order that supports collective ferroelectric behavior of the side groups as well as charge transport through the stacked semiconducting cores. The ferroelectric polarization in these supramolecular polymers is found to couple to the charge transport and leads to a bulk conductivity that is both switchable and rectifying. An intuitive model is developed and found to quantitatively reproduce the experimental observations. In a larger perspective, these results highlight the possibility of modulating material properties using the large electric fields associated with ferroelectric polarization.

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  • 35.
    Guo, Sisi
    et al.
    Shanghai Inst Technol, Peoples R China.
    Meng, Qiufeng
    Shanghai Inst Technol, Peoples R China.
    Qin, Jie
    Shanghai Inst Technol, Peoples R China.
    Du, Yong
    Shanghai Inst Technol, Peoples R China.
    Wang, Lei
    Shanghai Inst Technol, Peoples R China.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Le Febvrier, Arnaud
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Thermoelectric Characteristics of Self-Supporting WSe2-Nanosheet/PEDOT-Nanowire Composite Films2023In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 15, no 29, p. 35430-35438Article in journal (Refereed)
    Abstract [en]

    Conducting polymer poly(3,4-ethylenedioxythiophene) nanowires(PEDOTNWs) were synthesized by a modified self-assembled micellar soft-templatemethod, followed by fabrication by vacuum filtration of self-supportingexfoliated WSe2-nanosheet (NS)/PEDOT-NW composite films.The results showed that as the mass fractions of WSe2 NSsincreased from 0 to 20 wt % in the composite films, the electricalconductivity of the samples decreased from & SIM;1700 to & SIM;400S cm(-1), and the Seebeck coefficient increased from12.3 to 23.1 & mu;V K-1 at 300 K. A room-temperaturepower factor of 44.5 & mu;W m(-1) K-2 was achieved at 300 K for the sample containing 5 wt % WSe2 NSs, and a power factor of 67.3 & mu;W m(-1) K-2 was obtained at 380 K. The composite film containing5 wt % WSe2 NSs was mechanically flexible, as shown byits resistance change ratio of 7.1% after bending for 500 cycles ata bending radius of 4 mm. A flexible thermoelectric (TE) power generatorcontaining four TE legs could generate an output power of 52.1 nWat a temperature difference of 28.5 K, corresponding to a power densityof & SIM;0.33 W/m(2). This work demonstrates that the fabricationof inorganic nanosheet/organic nanowire TE composites is an approachto improve the TE properties of conducting polymers.

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  • 36.
    Ho Kim, Kyung
    et al.
    Chalmers University of Technology, Sweden.
    Lara-Avila, Samuel
    Chalmers University of Technology, Sweden; National Phys Lab, England.
    He, Hans
    Chalmers University of Technology, Sweden.
    Kang, Hojin
    Seoul National University, South Korea.
    Woo Park, Yung
    Seoul National University, South Korea.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Kubatkin, Sergey
    Chalmers University of Technology, Sweden.
    Thermal Stability of Epitaxial Graphene Electrodes for Conductive Polymer Nanofiber Devices2017In: Crystals, ISSN 2073-4352, Vol. 7, no 12, article id 378Article in journal (Refereed)
    Abstract [en]

    We used large area, monolayer graphene epitaxially grown on SiC (0001) as contact electrodes for polymer nanofiber devices. Our fabrication process, which avoids polymer resist residues on the graphene surface, results in graphene-polyaniline nanofiber devices with Ohmic contacts and electrical conductivity comparable to that of Au-nanofiber devices. We further checked the thermal stability of the graphene contacts to polyaniline devices by annealing up to T = 800 degrees C, the temperature at which polyaniline nanofibers are carbonized but the graphene electrode remains intact. The thermal stability and Ohmic contact of polymer nanofibers are demonstrated here, which together with the chemical stability and atomic flatness of graphene, make epitaxial graphene on SiC an attractive contact material for future all-carbon electronic devices.

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  • 37.
    Huniade, Claude
    et al.
    Univ Borås, Sweden.
    Melling, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Vancaeyzeele, Cedric
    CY Cergy Paris Univ, France.
    Nguyen, Giao T-M
    CY Cergy Paris Univ, France.
    Vidal, Frederic
    CY Cergy Paris Univ, France.
    Plesse, Cedric
    CY Cergy Paris Univ, France.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Bashir, Tariq
    Univ Borås, Sweden.
    Persson, Nils-Krister
    Univ Borås, Sweden.
    Ionofibers: Ionically Conductive Textile Fibers for Conformal i-Textiles2022In: Advanced Materials Technologies, E-ISSN 2365-709X, Vol. 7, no 10, article id 2101692Article in journal (Refereed)
    Abstract [en]

    With the rise of ion-based devices using soft ionic conductors, ionotronics show the importance of matching electronic and biological interfaces. Since textiles are conformal, an essential property for matching interfaces, light-weight and comfortable, they present as an ideal candidate for a new generation of ionotronics, i-textiles. As fibers are the building blocks of textiles, ionically conductive fibers, named ionofibers, are needed. However, ionofibers are not yet demonstrated to fulfill the fabric manufacturing requirements such as mechanical robustness and upscaled production. Considering that ionogels are known to be conformal films with high ionic conductivity, ionofibers are produced from commercial core yarns with specifically designed ionogel precursor solution via a continuous dip-coating process. These ionofibers are to be regarded as composites, which keep the morphology and improve the mechanical properties from the core yarns while adding the (ionic) conductive function. They keep their conductivity also after their integration into conformal fabrics; thus, an upscaled production is a likely outlook. The findings offer promising perspectives for i-textiles with enhanced textile properties and in-air electrochemical applications.

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  • 38.
    Inganäs, Olle
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin W. H.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Electrochemomechanical devices from polymer conductors and semiconductors2001In: Encyclopedia of materials: science and technology. Vol. 3 / [ed] K. H. Jürgen Buschow, Robert W. Cahn, Merton C. Flemings, Bernard Ilschner, Edward J. Kramer, Subhash Mahajan, and Patrick Veyssière, Oxford: Elsevier , 2001, 2, p. 2531-2535Chapter in book (Other academic)
    Abstract [en]

    Conjugated polymer (CP) actuators are devices where the volume of a CP material is changed during a change of the state of oxidation or reduction of the polymer. The volume change is extracted as a geo-metrical change in uni- or bimorphs, where the active material may be combined with the passive supporting material. In bimorphs, which have an active layer supported on a passive Ælm, bending of the assembly occurs as the dimensional change is driven by electrochemistry.

  • 39.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Actuators, biomedicine, and cell-biology2012In: Proceedings Volume 8340, Electroactive Polymer Actuators and Devices (EAPAD) / [ed] Y. Bar-Cohen, SPIE - International Society for Optical Engineering, 2012, p. 834006-1-834006-10Conference paper (Refereed)
    Abstract [en]

    Conducting polymers such as polypyrrole are well-known for their volume changing capacity and their use as actuating material. Actuators based on polypyrrole have been demonstrated in dimensions ranging from centimetres down to micrometres as well as in linear strain and bending beam actuation modes. The polypyrrole (micro-)actuators can be operated in salt solutions including cell culture media and blood. In addition, polypyrrole is known to be biocompatible making them a good choice for applications within cell biology and medicine. Applications of polypyrrole actuators within micromechanical devices, such as microrobotics and valves, will be presented. Opportunities and devices for the medical device industry, especially vascular surgery will be shown. This includes a rotating PCTA balloon system, a steerable guide wire, and an implantable drug delivery system. In addition, novel mechanostimulation chips for cell biology will be introduced. Using these devices, we can stretch cells and show the cellular response to this mechanical stimulation. Since the dawn of eukaryotic cells many parallel molecular mechanisms that respond to mechanical stimuli have evolved. This technology allows us to begin the investigation of these mechanisms on a single cell level.

  • 40.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Conducting Polymer Actuators for Medical Devices and Cell Mechanotransduction2013In: IEEE/ASME International Conference on Advanced Intelligent Mechatronics, 2013, IEEE , 2013, p. 1661-1666Conference paper (Refereed)
    Abstract [en]

    Actuators made of conjugated polymers such aspolypyrrole are interesting candidates as active elements inmedical devices since they can be fabricated in small sizes andoperated in saline solutions. In addition they can bemicrofabricated and integrated on silicon chips for instance forlab-on-a-chip and cell biology applications. Here, devicescomprising polypyrrole (PPy) microactuators for mechanicalstimulation of single cells are presented. In addition, novelinterfacing and patterning methods for conjugated polymer(micro-) actuators are reported that open up for enhancedfunctionality and increased complexity of micromanipulatorsand microrobotics for instance for biomedicine.

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  • 41.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Conducting polymers for cell biology and medical devices2014Conference paper (Refereed)
  • 42.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Electroactive fabrics for tissue engineering and softRobotics2015Conference paper (Other academic)
    Abstract [en]

    Electroactive polymers (EAP) such as conducting polymers are interesting materials not only forprinted, low cost electronics, photovoltaics and light emitting devices but also for use in soft actuators.These “smart” materials deform in response to electrical simulation and are often addressed asartificial muscles due to their functional similarity with natural muscles. The materials operate at lowvoltages, can use aqueous electrolytes and have been shown to be biocompatible. In addition since thematerials are both ion and electronic conductive they can be an interface between traditional hardelectronics that communicate by electrons and soft, wet biological materials such as tissue and cellsthat predominantly communicate by ionic signals. This makes the materials interesting candidates forbioelectronic applications including tissue engineering. Likewise the fact that they are lightweight andoperate silently makes them suitable as compliant actuators for soft robotics.Tissue engineering and stem cell therapy are the promising treatments of cardiac infarctions. Thestem cell niche is vital for the proliferation and differentiation of stem cells and tissue regeneration.An artificial carrier, e.g. a scaffold, is needed to introduce stem cells into the host tissue as directinjection of stem cells showed fast stem cell death. We are currently developing EAP scaffoldingfabrics for cardiac tissue engineering. The electrospun EAP scaffold mimics the extracellular matrixand provides a 3D microenvironment that can be easily tuned during fabrication, such as controllablefibre dimensions, alignment, and coating. In addition, the scaffold provides electrical andelectromechanical stimulation1 to the stem cells which are important external stimuli to stem celldifferentiation. This stimulation is expected to increase the differentiation ratio of stem cells intocardiomyocytes2,3. Excellent biocompatibility was achieved using primary cardiovascular progenitorcells4. We present the fabrication, electrochemical and electromechanical characterisation as well asthe response of the stem cells to the scaffolds and to the stimulation.Likewise we can use advanced textile technology to create a new type of soft actuators: electroactivetextiles. Textile technology allows for a rational assembly of fibres. We developed new EAP basedfibres, or yarn, employing a metal-free combined chemical-electrochemical synthesis route5 andassembled them in to EAP fabrics that show enhanced performance over individual fibres. We willpresent the fabrication and characterisation of these fibres and fabrics as well as their performance aslinear actuators.(1) Svennersten, K.; Berggren, M.; Richter-Dahlfors, A.; Jager, E. W. H. Lab on a Chip 2011, 11, 3287.(2) Shimizu, N.; Yamamoto, K.; Obi, S.; Kumagaya, S.; Masumura, T.; Shimano, Y.; Naruse, K.; Yamashita, J.K.; Igarashi, T.; Ando, J. Journal of Applied Physiology 2008, 104, 766.(3) Ghafar-Zadeh, E.; Waldeisen, J. R.; Lee, L. P. Lab on a Chip 2011, 11, 3031.(4) Gelmi, A.; Ljunggren, M.; Rafat, M.; Jager, E. W. H. Journal of Materials Chemistry B 2014, 2, 3860.(5) Maziz, A.; Persson, N.-K.; Jager, E. W. H. In Electroactive Polymer Actuators and Devices (EAPAD) 2012;Bar-Cohen, Y., Ed.; SPIE - International Society for Optical Engineering: San Diego, USA, 2015; Vol. 9430, p9430.

  • 43.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Electroactive polymers for bioelectronics and mechanostimulation2015Conference paper (Refereed)
  • 44.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Polypyrrole microactuators working in air2013Conference paper (Other academic)
  • 45.
    Jager, Edwin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Gaihre, Babita
    University of Wollongong, Australia.
    Alici, Gursel
    University of Wollongong, Australia.
    Spinks, Geoff
    University of Wollongong, Australia.
    Patterning of polypyrrole trilayer actuators working in air for microrobotics2012In: EuroEAP 2012 online proceedings, 2012Conference paper (Other academic)
    Abstract [en]

    Within the areas of cell biology, biomedicine and minimal invasive surgery, there is a need for soft and flexible manipulators for handling biological objects, such as single cells and tissues. Polypyrrole (PPy) trilayer actuators are an attracting option since they use low power, are soft and can be operated without the need of an external electrolyte. The PPy trilayer actuator is made of three layers laminated together: two outer two layers of PPy and a middle, insulating layer of polyvinylidene difluoride (PVDF) to separate the two electrodes and contain the electrolyte. To date, only simple, individual actuators as have been fabricated and characterized. For the applications mentioned previously there is a need to be able to also fabricate complex structures, comprising individual addressable microactuators, for instance, in the form of multi-degree of freedom legs and microrobotic grippers.

    We have developed different microfabrication and patterning methods for both thick, membrane PVDF- and thin film PVDF-based trilayer actuators, which require different processing steps, thus extendeding our processing capabilities. We will present these new processing methods and initial articulated microactuator devices, i.e. actuators comprising individually controllable actuators/segments.

  • 46.
    Jager, Edwin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Electrochemomechanical Devices from Conjugated Polymers2016In: Reference Module in Materials Science and Materials Engineering / [ed] Saleem Hashmi, Oxford: Elsevier, 2016, p. 1-5Chapter in book (Other academic)
    Abstract [en]

    Conjugated polymer actuators are devices where the volume of a conjugated (or conducting) polymer material is changed during a change of the state of oxidation or reduction of the polymer. This volume change can be utilized to construct actuators, for instance as a single layer or fiber resulting in a linear actuator or assembled into a multilayer structure where the active material is combined with a passive supporting material forming bending actuator.

  • 47.
    Jager, Edwin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Masurkar, Nirul
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Nworah, Nnamdi
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Gaihre, Babita
    University of Wollongong, Australia.
    Alici, Gursel
    University of Wollongong, Australia.
    Spinks, Geoff
    University of Wollongong, Australia.
    Individually controlled conducting polymer tri-layer microactuators2013In: Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII), 2013 Transducers & Eurosensors XXVII, IEEE , 2013, p. 542-545Conference paper (Other academic)
    Abstract [en]

    We are currently developing a range of microdevices based on polypyrrole (PPy) tri-layer microactuators that function in air. Here, we present recently developed microfabrication and patterning methods using photolithography for both thick, membrane and thin film poly(vinylidene difluoride) (PVDF) based PPy tri-layer actuators. We fabricated monolithically integrated, articulated actuator devices, i.e. comprising individually controllable actuators. We also introduce an interface for such PPy actuators based on a flexible printed circuit board, comprising the electrical contacts, into which the actuator device was inserted.

    Compartive evaluations showed that the microfabricated tri-layer actuators functioned as good as the normally fabricated actuators. The new interface seemed to actually improve the actuator performance.

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  • 48.
    Jager, Edwin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Maziz, Ali
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems.
    Khaldi, Alexandre
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems.
    Conducting Polymers as EAPs: Microfabrication2016In: Electromechanically Active Polymers: A Concise Reference / [ed] Federico Carpi, Cham: Springer, 2016, p. 293-318Chapter in book (Other academic)
    Abstract [en]

    In this chapter, first some basic principles of photolithography and general microfabrication are introduced. These methods have been adapted to fit the microfabrication of conducting polymer actuators, resulting in a toolbox of techniques to engineer microsystems comprising CP microactuators, which will be explained in more detail. CP layers can be patterned using both subtractive and additive techniques to form CP microactuators in a variety of configurations including bulk expansion, bilayer, and trilayer actuators. Methods to integrate CP microactuators into complex microsystems and interfaces to connect them to the outside world are also described. Finally, some specifications, performance, and a short introduction to various applications are presented.

  • 49.
    Jager, Edwin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Svennersten, Karl
    Karolinska Institute.
    Mechanotransduction in micturition studied using micromechanical stimulation chips2014Conference paper (Other academic)
  • 50.
    Johansson, Hanna
    et al.
    Linköping University, Department of Management and Engineering, Machine Design.
    Sundin, Maria
    Linköping University, Department of Management and Engineering, Machine Design.
    Produktutformning och materialval för formsprutning: beträffande polymera material2015Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    Injection molding is a manufacturing method that requires specific features to attain manufacturability. Gating suitability requires analysis and mere guidelines do not always provide the correct gate placement. Material selection requires a pronounced specification and is preferably supervised by an expert. Guidelines concerning design for manufacturing and assembly include, among other things, recommendations directly affecting the shape of the product. The aim for this bachelor thesis is to aid product developers and designers in taking manufacturing aspects into account early in the product development process. This is achieved by providing them with guidelines regarding material selection, injection molding, as well as design for manufacturing and assembly. The thesis is limited to thermoplastic materials suitable for injection molding and its results are based off thorough literature research, interviews and case studies. This bachelor thesis project, which is conducted at Linköping University,is a part of a project calledSafe manual assembly tools, and the resulting portable enabling device developed in Safe manual assembly toolsis used as case studies in this thesis. The case studies include: evaluation of concepts concerning manufacturability; material selection; and injection molding analysis through the software Moldflow. The thesis results in guidelines concerning design for manufacturing and assembly, injection molding and material selection. The case study is requited with concept selection suggestions, a selection of material that meets the specification of requirements stated in Safe manual assembly tools and design recommendations that aim to improve the manufacturability of the concept. This bachelor thesis concludes that design alterations striving to meet requirements for manufacturability should be made early in the devolpment process. Visiting the polymer-based product manufacturing industry offers better insight into which requirements that need to be fulfilled to make a product producible. Injection molding simulation software, if such is available, should be used in combination with design guidelines.The thesis also concludes that material selection is simplified through early contact with suppliers of material. Material selection is based off the specification of requirements and therefore requirements specified in the specification should be clarified and have their plausibility confirmed before the selection takes place.

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