Phototactic Miniature Soft Robots with Terrain Adaptability

Miniature locomotive robots that can adaptively change shapes to accommodate to various terrains have technologically significant applications ranging from noninvasive operations, environmental monitoring, to biomedical devices. However, existing miniature robots face two practical bottlenecks: limited mobility and low robustness, which severely restrict their applicability. In this work, terrain-adaptive miniature soft robots that can be powered, guided, and maneuvered on challenging terrains by a versatile phototactic strategy are created. These robots, constructed by a rationally designed liquid crystal elastomer with powerful photomechanical actuation, enable self-actuation to generate autonomous and self-sustained rolling locomotion under constant near-infrared light stimuli without any on-off switching. They outperform previous light-driven miniature robots and exhibit exceptional terrain adaptability to traverse a diversity of simple and complex terrains, and even hybrid terrains with varying topology, mechanics, and rheology. The terrain-adaptive robots can directionally leap over hurdlers, and even exert high jumping to overcome high wall obstacle. It is envisioned that this proposed technique would enable the design of miniature mobile robots that can accommodate varying terrains and fulfill multiple tasks in unpredictable environments.