Adhesive Microstructures: Anisotropic Adhesion Properties of Triangular‐Tip‐Shaped Micropillars (Small 16/2011)

The cover image illustrates the anisotropic adhesion property of triangular-tip-shaped micropillars, which are proposed as a new design for bio-inspired adhesive structures. These unique micropillars show directional shear adhesion with respect to the change of peeling direction (8.8–17.2 J m−2) as well as relatively high normal adhesion (8.2–10 N m−2). The directional adhesion is ascribed to the propagation line of cracks under triangular contact domains. When cracks initiate from the vertex, they can easily propagate to the inner region, resulting in relatively lower shear adhesion. In contrast, when peeled from the side of the triangle, the cracks form a pseudoline contact, and thus the crack propagation is retarded. For more information, please read the Communication “Anisotropic Adhesion Properties of Triangular-Tip-Shaped Micropillars” by K. Y. Suh and co-workers, beginning on page 2296.