Kirigami-Inspired Structures for Smart Adhesion.

ABSTRACT

Spatially controlled layouts of elasticity can provide enhanced adhesion over homogeneous systems. Emerging techniques in kirigami, where designed cuts in materials impart highly tunable stiffness and geometry, offer an intriguing approach to create well-defined layouts of prescribed elastic regions. Here, we show that kirigami-inspired structures at interfaces provide a new mechanism to spatially control and enhance adhesion strength while providing directional characteristics for smart interfaces. We use kirigami-inspired cuts to define stiff and compliant regions, where above a critical, material-defined length scale, bending rigidity and contact width can be tuned to enhance adhesive force capacity by a factor of ∼100 across a spatially patterned adhesive sheet. The directional nature of these designs also imparts anisotropic responses, where peeling in different directions results in anisotropic adhesion ratios of ∼10. Experimental results are well-supported by theoretical predictions in which the bending rigidity and contact width of kirigami-inspired structures and interconnects control the adhesive capacity. These new interfacial structures and design criteria provide diverse routes for advanced adhesive functionality, including spatially controlled systems, wearable kirigami-inspired electronics, and anisotropic kirigami-inspired bandages that enable strong adhesive capacity while maintaining easy release.