Soft electroactive actuators and hard ratchet-wheels enable unidirectional locomotion of hybrid machine

Wenjie Sun,Ziqi Ma,Chenghai Li,Fan Liu,Jinxiong Zhou

doi:10.1063/1.4975145

Abstract

Combining synergistically the muscle-like actuation of soft materials and load-carrying and locomotive capability of hard mechanical components results in hybrid soft machines that can exhibit specific functions. Here, we describe the design, fabrication, modeling and experiment of a hybrid soft machine enabled by marrying unidirectionally actuated dielectric elastomer (DE) membrane-spring system and ratchet wheels. Subjected to an applied voltage 8.2 kV at ramping velocity 820 V/s, the hybrid machine prototype exhibits monotonic uniaxial locomotion with an averaged velocity 0.5mm/s. The underlying physics and working mechanisms of the soft machine are verified and elucidated by finite element simulation.

Highlights

Among various soft active materials explored so far, tremendous interests have been drawn to the use of electroactive dielectric elastomer (DE) to design and fabricate soft actuators, sensors, generators, robotics, and even airships.[10,11,12,13,14,15]
A piece of DE membrane with compliant electrodes on top and bottom surfaces would expand in area and reduce in thickness when subjected to an applied voltage
Following our previous efforts on hybrid soft machines driven by foldable DE actuators,[20] we marry these two unidirectional strategies rigid bars constrained DE elastomers and ratchet wheels to achieve monotonic uniaxial locomotion of machines

Summary

Introduction

Conventional rigid-bodied hard machines are extensively used in manufacturing, transportation, electrical systems, mechanical and energy components, robots, and aerospace structures, but they are complex, expensive, unsafe to human interaction, and lack of adaptability.[1,2,3,4,5,6,7] In contrast to their hard counterparts, the emerging soft machines are primarily composed of soft materials, and can exhibit unprecedented adaption, sensitivity and agility.[1,2,3,4] Soft machines are easy to construct, cheap, easy to control, and environmentally friendly. Soft electroactive actuators and hard ratchet-wheels enable unidirectional locomotion of hybrid machine A synergistic combination of hard mechanical components and soft actuators results in hybrid soft machines that can perform desirable tasks.

Results

Conclusion