Miniaturized ionogel-based bi-stable actuator with state-sensing capability

Abstract

This work reports a miniaturized actuator with state-sensing and bi-stable capabilities that was developed by utilizing the shape memory effect of ionogel. The actuator consists of a carbon nanotube (CNT) dispersed ionogel finger, a thermo-responsive liquid-crystal elastomer (LCE) cantilever, and a micromachined heater layer. The LCE cantilever serves as an actuating material for deforming the ionogel finger, while the heater layer is used to induce LCE deformation by elevating the LCE temperature. Due to the one-way shape memory effect, the ionogel finger possesses bistability with large deformations, and is capable of staying in either position without consuming energy. The ionogel finger also functions as a sensing material for detecting its state in a sensorless fashion. A bi-stable gripper constructed by assembling two proposed actuators was demonstrated and characterized. In addition, a video demonstration showed that the gripper could grasp and stably hold heavy metal objects without consuming any power because of its bistability.