Scalable functionalized shape memory alloy fiber with synergistic effect for robotic hand and microrobot

Abstract

Shape memory alloy (SMA) fibers demonstrate exceptional contraction strains and substantial load capacities, positioning them as highly promising actuators for advanced robotic hands and microrobotic systems. However, the practical deployment of SMAs has been critically hindered by their inherently slow thermal responsiveness and reliance on wired electrical connections. Here, we introduce a dual-responsive SMA technology that addresses these limitations by leveraging a novel surface modification comprising polydopamine integrated with silver nanowires. The modified SMA fibers exhibited an approximately 3.2 times faster actuation speed than unmodified fibers under near-infrared laser irradiation, with a 35% improvement in electrothermal responsiveness. These wireless, fast-responding actuators have been effectively integrated into microrobotic crawlers, demonstrating great potential for lightweight autonomous lunar rover applications. Fabricated via straightforward in-situ polymerisation methods, our dual-responsive SMA approach offers a compelling pathway toward the development of energy-efficient aerospace systems capable of operating reliably under extreme environmental conditions.