Simultaneous 3D Forming and Patterning Method of Realizing Soft IPMC Robots

Abstract

Ionic polymer-metal composites (IPMC) actuators are popular because they can be driven at a low voltage, possess excellent responsiveness, and can perform soft motions similar to that of living creatures. Conventional IPMC soft robots are manufactured by cutting and assembling IPMC sheets. However, using this conventional process to stably manufacture three-dimensional (3D)-shaped soft robots is difficult. To mitigate this problem, we propose a new method for fabricating 3D IPMC actuators in which several surface electrodes are separately fabricated from a single ion-exchange membrane. We refer to our proposal as the simultaneous 3D forming and patterning (SFP) method. Unlike the conventional IPMC fabrication process, the SFP method requires only one step to fix the ion-exchange membrane to contact masks. First, we briefly describe IPMC actuators, before introducing the proposed SFP method in detail. Next, we describe our investigations of the patterning resolution for the surface electrode using the proposed method. We fabricated two soft robot prototypes using the proposed method. The first robot is a starfish-type soft robot. Its surface electrode can be patterned in a plane using the proposed method, and independent driving is possible by applying voltage individually to the divided electrodes. The second prototype is a sea anemone-type soft robot, wherein surface electrodes can be patterned on a 3D curved surface to form a 3D shape.