2, Linköping University, Linköping, , Sweden
Soft machines and soft robots are on the move and much heard of. One of the industrially most employed ways of making soft materials is textiles, still textiles is not that explored within the actuator and soft robotics community. The inherent properties of textile being fiber based i.e. being an assembly of prolonged building blocks (filaments, yarns etc.) intertwined in different ways such as by weaving and knitting offers highly interesting possibilities. These embrace pliability, toughness, drapability, proximity to humans in all aspects of daily life, up-scaling and large area production with reproducible, high speed manufacturing.
Here we employ the rich possibilities of textiles by making all-polymer actuating textile devices based on electroactive polythiophene and polypyrrol structures, denoted textuators. Redox based ion migration and electrical voltage controlled steering has for a long time been the mean for achieving actuation where implicitly wet electrochemistry has been the paradigm. We show that textile actuation is possible following this pathway. Looking upon a single warp thread as an actuating element we show that both a) force and b) strain could be amplified by the textile assembly processes applied, following a linear up-scaling. Furthermore, we also show that it is possible to transfer this logic to a dry, in-air-situation. We have designed textile actuators working with solid electrolytes, decouple the actuating functionality from wet chemistry and advancing the electroactive polymer based actuator range of use. Specifically, a trilayer textile composite of a) a conducting polymer textile actuator, b) a solid polymer electrolyte (SPE) and c) a conducting polymer textile actuator was constructed using an SPE based on thiol acrylate Michael chemistry allowing ionic exchanges and obtaining bending movements in air. This opens up for highly interesting future applications such as soft, compliant, textile exo-skeletons for assistive devices possible to be produced effectively.