Untethered thin dielectric elastomer actuated soft robot

TL;DR

This paper introduces an untethered soft robot powered by thin dielectric elastomer actuators, capable of navigating confined spaces with low voltage and integrated electronics, advancing soft robotics for complex environments.

Contribution

The study presents a novel untethered soft robot with integrated electronics and low-voltage dielectric elastomer actuators, enabling high-speed locomotion in confined spaces.

Findings

Achieved 12.36 mm/s speed at resonance with the TS-DEA

Untethered robot reaches 0.5 mm/s locomotion speed

Operates at low voltage of 220 V and 86 Hz resonance

Abstract

Thin dielectric elastomer actuator (DEA) features a unique in-plane configuration, enabling low-profile designs capable of accessing millimetre-scale narrow spaces. However, most existing DEA-powered soft robots require high voltages and wired power connections, limiting their ability to operate in confined environments. This study presents an untethered thin soft robot (UTS-Robot) powered by thin dielectric elastomer actuators (TS-DEA). The robot measures 38 mm in length, 6 mm in height, and weighs just 2.34 grams, integrating flexible onboard electronics to achieve fully untethered actuation. The TS-DEA, operating at resonant frequencies of 86 Hz under a low driving voltage of 220 V, adopts a dual-actuation sandwiched structure, comprising four dielectric elastomer layers bonded to a compressible tensioning mechanism at its core. This design enables high power density actuation and locomotion via three directional friction pads. The low-voltage actuation is achieved by fabricating each elastomer layer via spin coating to an initial thickness of 50 um, followed by biaxial stretching to 8 um. A comprehensive design and modelling framework has been developed to optimise TS-DEA performance. Experimental evaluations demonstrate that the bare TS-DEA achieves a locomotion speed of 12.36 mm/s at resonance, the untethered configuration achieves a locomotion speed of 0.5 mm/s, making it highly suitable for navigating confined and complex environments.