Design and Fabrication of 3D Papercraft IPMC Robots

Abstract

Ionic-polymer metal composites (IPMC) actuators, which are typical polymer gel actuators, can be driven at a low voltage and provide high responsiveness and large displacement. Conventional robots using IPMC actuators were generally fabricated by cutting and pasting sheet-shaped IPMCs, which posed a problem in realizing complex three-dimensional (3D) shapes and motions. To address this problem, we previously proposed a fabrication method (Simultaneous 3D Forming and Patterning, SFP) that simultaneously achieves a 3D shape using the shape memory property of the ion-exchange membrane and segments the IPMCs by masking with a jig. However, the shapes that can be formed by SFP method are limited to those that can be formed just by bending the sheets, which should be extended to more complicated shapes of IPMCs. Therefore, in this paper, we propose a new type of 3D IPMC robots inspired by papercrafts that can form their shapes like “papercrafts” with a combination of SFP process and a clinching method in joining. Clinching for the ion-exchange membrane enables joining adjacent surfaces of thin-walled IPMC robots, allowing the fabrication of IPMC robots like papercrafts. After clarifying the joint strength of clinching for ion-exchange membrane, two turtle-shaped papercraft IPMC robots were designed and prototyped in two different sizes, which have highly complex 3D shapes. The prototype robots achieved the designed shapes and succeeded in the fundamental driving experiments.