Dendrite Growth and Performance of Self-Healing Composite Electrode IPMC Driven by Cu2+

As a kind of flexible intelligent driving material, ionic polymer-metal composite (IPMC) has attracted the attention of researchers due to its advantages of lightweight, large deformation, and fast response. However, the reciprocating bending of IPMC causes cracks to appear on the surface metal electrode layer and reduces the water uptake (WUP). At the same time, the metal particles are extruded, resulting in an increase in resistivity, which affects the driving performance of the materials. Therefore, in this study, considering the preparation cost, Cu-Pt-IPMC using Pt and Cu as a composite electrode with the self-healing system was prepared by electroless plating and Cu2+ was used as driving ions that can form a reversible circulation system with a copper electrode. The WUP, surface resistivity, and driving performance were tested and analyzed and the surface roughness was characterized by Matlab. The results show that the dendritic interface electrodes (DIEs) appear at the contact interface between the metal electrode and the film, which extend deeper and wider in the film with the increase in the cycles of autocatalytic platinum plating (ACP-Pt), and the output displacement and blocking force of 61.20 mm and 34.26 mN, respectively, have been achieved in the Cu-Pt-IPMC sample after three cycles of ACP-Pt. Based on these analyses, this study proves that the presence of Cu2+ can repair the cracked electrode on the surface of IPMC and reduce the surface electrode resistance, improving the driving performance.