3D-printed PEDOT:PSS for soft robotics

Soft robotics is an emerging technology requiring conductive materials with inherently high compliance to sense, control or actuate. Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is a soft and flexible conducting polymer with tunable mechanical properties, mixed ionic and electronic conductivity and excellent processability. Combining PEDOT:PSS with advanced 3D printing has ushered unprecedented opportunities in soft material engineering and soft robotics. In this Review, we aim to bridge the gap between different research areas by specifically discussing the use of PEDOT:PSS-based inks in 3D printing for soft robotics. We discuss rational PEDOT:PSS-based ink design and evaluation, 3D-printing technologies and strategies as well as applications for soft robotics. We provide insights into the theoretical background and fundamental aspects of the 3D printing of conducting polymers, with the goal of accelerating soft robotics development. Combining poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) with 3D-printing techniques enables the customization of compliant conductive materials for soft robotics, towards the goal of merging humans and robots. This Review discusses the fundamentals of 3D-printed PEDOT:PSS for soft robotics, from printable ink design and evaluation to printing strategies and promising soft robotic systems.