Overcoming directional constraints in adhesives: λ-patterned kirigami for programmable adhesion and surface conformability

Smart adhesives, as a novel class of materials combining controllable adhesion and facile detachment, show great potential for applications in wearable devices and flexible electronics. However, existing adhesive systems exhibiting directional or adaptive adhesion often rely on globally coupled deformation or interface states, which limits independent and predictable regulation of adhesion along different directions. In this study, we propose a multi-directionally programmable adhesive based on a λ (lambda)-patterned kirigami structure, which leverages the pattern’s geometric asymmetry to facilitate directional adhesion, enabling independent regulation of adhesion performance in different directions without external stimuli. Using a precisely designed kirigami cutting strategy, we achieve decoupled mechanical responses along two orthogonal in-plane directions, yielding pronounced directional contrast and high adhesion enhancement ratios. Experimental results reveal that the structure attains a maximum of 20-fold directional contrast and 35-fold adhesion enhancement, while maintaining conformability to surfaces with varying Gaussian curvatures. To demonstrate practical utility, the kirigami design is implemented as a medical adhesive tape, providing reliable adhesion, resistance to disturbances, and directionally programmable, low-trauma detachment with a simple direction-dependent patterning demonstration. This kirigami-guided strategy offers a structurally tunable platform for anisotropic adhesion, laying a foundation for smart adhesive interfaces in complex environments.