Bioinspired Tribologically Induced Liquid Metal Nanoparticle Coatings with Super-Lyophobic Characteristics for Soft Robotics

Magnetic liquid metal (MLM) offers high conductivity and fluidity from gallium-based alloys, combined with magnetic responsiveness, enabling dynamic deformation, programmable motion, and self-healing. These properties make MLM attractive for stretchable electronics, soft robotics, and smart sensing. However, achieving precise, programmable, non-adhesive manipulation of MLM in a solution-free environment remains a critical challenge. Inspired by friction-induced aggregation of soft particles during skin cream application, a facile tribological method for producing super-lyophobic liquid metal (LM) nanoparticle coatings on diverse metal and non-metal substrates, including those with regular and complex geometries, is reported. The tribological process fragments bulk LM into stable nanoparticles with a liquid-core–solid-shell structure, which assemble into densely packed, nanoscale-textured coatings that effectively repel MLM droplets while preserving the electrical conductivity of the underlying metal substrate. Owing to this unique coating, MLM droplets exhibit excellent non-wettability and highly controllable motion under magnetic actuation. This strategy enables versatile functional applications, including magnetically actuated electronic switches with enhanced reliability, rapidly printed stretchable MLM circuits with high mechanical robustness, and bioinspired soft robotic systems mimicking mollusk-like locomotion with superior shape adaptability. The experimental results demonstrate that the proposed strategy enables precise MLM control, advancing next-generation stretchable electronics and soft robotics.