Air-Working Electrochromic Artificial Muscles.

Artificial muscles are indispensable components for next-generation robotics to mimic the sophisticated movements of living systems and provide higher output energies when compared with real muscles. However, artificial muscles actuated by electrochemical ion injection have problems with single actuation properties and difficulties in stable operation in air. Here, we report air-working electrochromic artificial muscles (EAMs) with both color-changing and actuation functions, which are constructed based on vanadium pentoxide nanowires and carbon tube yarn. Each EAM can generate a contractile stroke of approximately 12% during stable operation in the air with multiple color changes (yellow-green-gray) under ±4 V actuation voltages. The reflectance contrast is as high as 51%, demonstrating the excellent versatility of the EAMs. Additionally, we have constructed a toroidal EAM arrangement with fast response and high resilience. The EAM's contractile stroke can be displayed through visual color changes, which provides new ideas for future artificial muscle applications in soft robots and artificial limbs. This article is protected by copyright. All rights reserved.