Handling of soft and fragile sub-millimeter sized samples such as cells and tissues requires new tools that allow delicate manipulation. Conducting polymer actuators show unique characteristics suitable to driving such manipulators, however despite their potential, the current fabrication method of the trilayer structures does not allow constructing advanced micromanipulators operating in air using this technology. Here we show a novel bottom-up microfabrication process for conjugated polymer trilayer actuators using various solid polymer electrolytes. In addition, the process design integrates contact pads, which has been an issue for small scale conducting polymer actuators. The microfabrication process starts with a patterned layer of conjugated polymer, followed by depositing a polymer electrolyte and a second patterning of the second conjugated polymer layer. The process resulted in successful fabrication of individually controllable conducting polymer trilayer actuators comprising polyvinylidenefluoride and poly( vinylidenefluoride-co-hexafluoropropylene) membranes and showed good interfacial adhesion between the different layers in the final device. The polyvinylidenefluoride trilayer actuator showed good actuation capability. The developed bottom-up microfabrication method paves the way for the development of novel micromanipulation tools. (C) 2016 Elsevier B.V. All rights reserved.

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.

We are developing soft, flexible micromanipulators such as micro- tweezers for the handling and manipulation of biological species including cells and surgical tools for minimal invasive surgery. Our aim is to produce tools with minimal dimensions of 100 μm to 1 mm in size, which is 1-2 orders of magnitude smaller than existing technology. However, the displacement of the current developed micromanipulator remains limited due to the low ionic conductivity of the materials. Here, we present developed methods for the fabrication of conjugated polymer trilayer structure which exhibit potential to high stretchability/flexibility as well as a good adhesion between the three different layers. The outcomes of this study contribute to the realisation of low-foot print devices articulated with electroactive polymer actuators for which the physical interface with the power source has been a significant challenge limiting their application. Here, we present a new flexible trilayer structure, which will allow the fabrication of metal-free soft microactuators.

Cellular mechanotransduction is crucial for physiological function in the lower urinary tract. The bladder is highly dependent on the ability to sense and process mechanical inputs, illustrated by the regulated filling and voiding of the bladder. However, the mechanisms by which the bladder integrates mechanical inputs, such as intravesicular pressure, and controls the smooth muscles, remain unknown. To date no tools exist that satisfactorily mimic in vitro the dynamic micromechanical events initiated e.g. by an emerging inflammatory process or a growing tumour mass in the urinary tract. More specifically, there is a need for tools to study these events on a single cell level or in a small population of cells. We have developed a micromechanical stimulation chip that can apply physiologically relevant mechanical stimuli to single cells to study mechanosensitive cells in the urinary tract. The chips comprise arrays of microactuators based on the electroactive polymer polypyrrole (PPy). PPy offers unique possibilities and is a good candidate to provide such physiological mechanical stimulation, since it is driven at low voltages, is biocompatible, and can be microfabricated. The PPy microactuators can provide mechanical stimulation at different strains and/or strain rates to single cells or clusters of cells, including controls, all integrated on one single chip, without the need to preprepare the cells. This paper reports initial results on the mechano-response of urothelial cells using the micromechanical stimulation chips. We show that urothelial cells are viable on our microdevices and do respond with intracellular Ca2+ increase when subjected to a micro-mechanical stimulation.

Two self-doped conjugated polyelectrolytes, having semiconducting and metallic behaviors, respectively, have been blended from aqueous solutions in order to produce materials with enhanced optical and electrical properties. The intimate blend of two anionic conjugated polyelectrolytes combine the electrical and optical properties of these, and can be tuned by blend stoichiometry. In situ conductance measurements have been done during doping of the blends, while UV vis and EPR spectroelectrochemistry allowed the study of the nature of the involved redox species. We have constructed an accumulation/depletion mode organic electrochemical transistor whose characteristics can be tuned by balancing the stoichiometry of the active material.

We have developed a micromechanical stimulation chipthat can apply physiologically relevant mechanical stimulito single cells to study mechanosensitive cells in the urinarytract. The chips comprise arrays of microactuators based onthe electroactive polymer polypyrrole (PPy). PPy offersunique possibilities and is a good candidate to provide suchphysiological mechanical stimulation, since it is driven atlow voltages, is biocompatible, and can be microfabricated.The PPy microactuators can provide mechanical stimulationat different strains and/or strain rates to single cells orclusters of cells, including controls, all integrated on onesingle chip, without the need to pre-prepare the cells. Thechips allow for in situ stimulation during live imagingstudies. The use of these devices will increase experimentalquality and reduce the number of biological samples. Theseunique tools fill an important gap in presently availabletools, since the chips provide array-based stimulationpatterns and are easily integrated in existing cell biologyequipment. These chips will generate a leap forward in ourunderstanding of the mechanisms involved inmechanotransduction in cells that may lead to breakthroughs,for instance in therapies for urinary incontinence.