Sensing-triggered stiffness-tunable smart adhesives

Artificial dry adhesives have exhibited great potential in the field of robotics. However, there is still a wide gap between bioinspired adhesives and living tissues, especially regarding the surface adaptability and switching ability of attachment/detachment. Here, we propose a sensing-triggered stiffness-tunable smart adhesive material, combining the functions of muscle tissues and sensing nerves rather than traditional biomimetic adhesive strategy that only focuses on structural geometry. Authorized by real-time perception of the interface contact state, conformal contact, shape locking, and active releasing are achieved by adjusting the stiffness based on the magnetorheological effect. Because of the fast switching of the magnetic field, a millisecond-level attachment/detachment response is successfully achieved, breaking the bottleneck of adhesive materials for high-speed manipulation. The innovative design can be applied to any toe's surface structure, opening up a previously unknown avenue for the development of adhesive materials.