Toward a High‐Performance Ionic Soft Actuator: A Disturbance-Aided Method for Elimination of Back Relaxation of Pattern-Free Ipmc Actuators

Abstract

Besides the advantages of Ionic polymer-metal composites (IPMCs) for biomedical applications, there are some drawbacks in their performance, which can be enhanced. One of those critical drawbacks is "back relaxation" (BR). If we apply a step voltage to IPMC, it will bend in the anode direction. Afterward, there is an unwanted and relatively slow counter-bending toward the cathode side. There are some disadvantages in the current BR control methods of IPMC actuators that prevent them from being used in real applications. This paper presents a new non-feedback method for eliminating the BR effect of non-patterned IPMCs by using a relatively high-frequency disturbance and proving it by theoretical and experimental explanations. The results show that the proposed method, needless to have any pattern on the electrodes of the IPMCs, can significantly eliminate the BR effect. Unlike the patterned IPMCs, no reduction will occur in the bending amplitude of IPMC, and even we can see the increased bending amplitude.

Keywords: IPMC, Actuator, Back Relaxation (BR), non-feedback, non-patterned.