Micropillar-Engineered Hybrid Adhesive Patch for Surface-Conformable and Directional Adhesion

Abstract

The development of smart adhesives capable of robust and reusable adhesion on rough surfaces remains challenging. Intimate microscale contact is essential for strong adhesion, but irregular topographies hinder conformal engagement and limit both adhesion strength and repeatability. Here, we introduce a surface-conformable hybrid adhesive integrating height-optimized hexagonal micropillars with nonlinear open cuts, coupling microscale adaptability with macroscale crack-guiding mechanics. Height optimization enhances rough-surface contact and adhesion, while engineered cuts guide and reverse interfacial cracks to provide direction-dependent detachment. This hybrid architecture achieves a pull-off strength of 79.5 kPa, peel energy of 106.3 N m−1, >100-cycle durability, and 20× directional contrast on substrates with RMS roughness of 20.1 µm. Integration into a robotic gripper confirms reliable grasp–release operation, highlighting potential applications in wearables, robotics, and biomedical devices