Gecko's Feet-Inspired Self-Peeling Switchable Dry/Wet Adhesive

Abstract

Dynamic switchable attachment/detachment behavior can be extensively observed in biological systems. Although wide interest has been focused on the fabrication of biomimetic synthetic switchable adhesives, designing intelligent adhesive material systems under both dry and wet conditions by following a peeling mechanism from mechanical deformation-induced adaptive evolution of the interface geometric contact state is still challenging. Herein, inspired by the rolling behavior of gecko's feet, one kind of novel multilayered self-peeling switchable dry/wet adhesive (SPSA) is developed by integrating thermal-responsive hydrogel layers, gecko's feet-inspired mushroom-structured arrays, and mussel-inspired copolymer adhesive coatings together. The SPSA shows thermal-responsive curving behavior along with switchable dry and underwater adhesion. Theoretical analysis is performed for explaining the dynamic curvature-induced switchable peeling mechanism. By integrating Fe3O4 nanoparticles into the SPSA, remote control over switchable adhesion can be achieved by applying near-infrared laser radiation. Considering potential applications, the SPSA can be used for successfully bonding/separating and capturing/releasing objects in air and in underwater environments. This research provides a new route for developing intelligent adhesion systems and mobile devices/robots.