Micropillar-Enabled Tough Adhesion and Enhanced Sensing

This work presents a hyperbranched polyurethane-based micropillared interface that simultaneously achieves high interfacial toughness and enhanced sensing performance in soft multilayer iontronic sensors. By tuning the micropillar geometry such that pillar diameter falls below the flaw sensitivity length, the interface eliminates critical defects, achieving an exceptional interfacial toughness of 5,095 J m⁻². These micropillars function dually as robust adhesion structures and adaptive elastic spacers, enhancing pressure sensitivity and enabling detection of high-frequency signals up to 7,000 Hz. The micropillared design offers a generalizable route for developing skin-like sensors with superior adhesion, durability, and mechanical adaptability for humanoid robotics and wearable technologies.