Rapidly Switchable Core–Shell Smart Adhesives Triggered by Magnetic Field

Smart artificial dry adhesives hold promise in robotics and transfer technologies, yet a gap remains with bioinspired adhesives due to adhesion conflict (where the adhesive must be soft for surface adaptability but also hard to withstand high pull-load). And the switchability required for most application imposes an even bigger challenges. Here, we introduce a magnetic field-triggered core-shell smart dry adhesive, comprising a PDMS-shell and MRG-core, to address these hurdles and achieve rapid switchable adhesion on diverse surfaces. Utilizing the magnetorheological effect, we adjust stiffness to enable conformal contact, shape-locking, and active releasing. Moreover, magnetic field application transitions the material from "soft core-hard shell" to "hard core-soft shell", facilitating interface stress tunability. The millisecond-level attachment/detachment response and excellent repeatability, enabled by MRG's magnetic response, facilitates high-speed manipulation. This innovative design, integrating material and structural regulation to achieve functional versatility, guides the advancement of stronger, switchable, and adaptable adhesives. Its impact extends to fields like adhesive grabbers and climbing robots, which demand precise and rapid motions.