Shape Memory Polymer-Based Switchable Bioinspired Microstructured Dry Adhesives.

Abstract

Reconciling strong adhesion with easy detachment remains a fundamental challenge for interfacial science. Here, we present a switchable bioinspired microstructured dry adhesive utilizing shape memory polymers (SMPs). By exploiting the shape memory effect to dynamically modulate the material modulus and contact area, the adhesive achieves a maximum adhesion strength of 525 kPa, an adhesion-to-preload ratio of 2.6, and a switching ratio of 5.4. We elucidate the underlying buckling instability and shape memory mechanisms, establishing an adhesion model based on a bilinear-cohesive-zone approach. The adhesive demonstrates a 90.3% self-cleaning efficiency, high stability against surface roughness variations, and durability exceeding 400 cycles across a diverse range of substrates. Finally, we demonstrate its practical utility through grasping complex objects and enabling unmanned aerial vehicles (UAVs) to perch and relaunch on various surfaces.