Vinyl acetate-enhanced polyvinyl chloride gel with high electroadhesion and self-heating-tunability for soft robots in freezing environments

Abstract

Polyvinyl chloride gel (PVCg) exhibits versatile electromechanical properties, making it highly promising for soft robots. However, conventional PVCg with excessive plasticizers generates a significant amount of heat and suffers from premature electrical breakdown during electro-induced actuation, seriously limiting its widespread application. Here, a novel strategy is demonstrated to simultaneously regulate the heat generation and improve the electromechanical properties of PVCg by introducing polyvinyl chloride-co-vinyl acetate (PVCVA) to fabricate PVCVA gel (PVCVAg). Notably, the proposed PVCVAg exhibits over 50% reduction in heat generation, 15-fold extended lifespan (from 200 s to over 3000 s), and 2.15 times higher electro-adhesion force (from 13.8 to 29.6 kPa) compared to the state-of-the-art PVCg. Based on the improved electroactive properties of PVCVAg, electro-actuation, adhesion, and tunable heating are integrated into a soft robot to achieve fast crawling, module self-reconfiguration within millimeter dimensions via electroadhesive connections, and on-demand environmental thermal interaction without requiring auxiliary heaters. Moreover, these capabilities are validated through various tests, including self-reconfiguration in maze-like confined spaces, operation at −50 °C, and collaborative aero-engine blisk inspection and ice melting in freezing environments. These demonstrations highlight the application potential of the integrated multifunctional PVCVAg devices in complex and extreme environments.