Water-Repellent, Surface-Adaptive, and Switchable Adhesive Patch Using Microstructured Shape Memory Polymers

Abstract

Strong yet switchable adhesion in wet environments remains a critical challenge for applications spanning underwater robotics, biointerfaces, and adaptive gripping systems. Conventional wet adhesives suffer from limited surface adaptability, loss of adhesion due to interfacial water, and poor controllability. Here, we report a multifunctional adhesive patch that integrates superhydrophobic micropillar arrays with a thermoresponsive shape memory polymer (SMP) matrix to simultaneously achieve water-shedding capability, robust underwater adhesion, and thermally programmable detachment. The micropillar geometry repels interfacial water and establishes a dry contact, while the SMP matrix dynamically tunes modulus and contact geometry through reversible glassy–rubbery transitions, enabling conformal adaptation and recovery-driven detachment. As a result, the patch demonstrates exceptional underwater pull-off strength (612.5 kPa), a high switching ratio (Fon/Foff = 46.3), and excellent durability over 500 cycles. Furthermore, when integrated into a thermally controlled robotic gripper, the patch successfully performs submerged pick-and-place operations on rough and irregular substrates, highlighting its potential for next-generation underwater manipulation, soft robotics, and smart biomedical adhesives.