Soft Electrothermal Meta-Actuator for Robust Multifunctional Control

TL;DR

This paper introduces a novel soft electrothermal meta-actuator that achieves bidirectional motion, environmental robustness, and faster response times through engineered heat transfer, enabling advanced soft robotics applications.

Contribution

The work presents a meta-actuator architecture that overcomes traditional thermally induced actuation limitations by enabling multifunctional, bidirectional, and rapid actuation with environmental insensitivity.

Findings

Achieves bidirectional motion with large deflections (≥28%) at 0.75 W

Reduces thermal sensitivity to ambient temperature by over 100 times

Faster return to rest state, 10 times quicker than passive cooling

Abstract

Soft electrothermal actuators are of great interest in diverse application domains for their simplicity, compliance, and ease of control. However, the very nature of thermally induced mechanical actuation sets inherent operation constraints: unidirectional motion, environmental sensitivity, and slow response times limited by passive cooling. To overcome these constraints, we propose a meta-actuator architecture, which uses engineered heat transfer in thin films to achieve multifunctional operation. We demonstrate electrically selectable bidirectional motion with large deflection ($ \geq $28% of actuator length at 0.75 W), suppressed thermal sensitivity to ambient temperature changes when compared to conventional actuators (>100$ \times $ lower), and actively forced return to the rest state, which is 10 times faster than that with passive cooling. We further show that our meta-actuator approach enables extended ranges of motions for manipulating complex objects. Versatile soft gripper operations highlight the meta-actuator's potential for soft robotics and devices.