Close-up of mushroom-shaped fibrillar adhesive microstructure: contact element behaviour.

To analyse the performance of mushroom-shaped fibrillar adhesive microstructure, its behaviour was studied during different stages of attachment-loading-detachment cycle. Visualizing the evolutions of real contact area of single microfibres, it is shown that the mushroom-shaped geometry of contact elements promotes fast and simple generation of reliable adhesion. The mushroom-shaped geometry seems to transform fibrillar contact elements into passive suction devices and makes them tolerant to overload, thus enhancing their robustness and stability. These findings may also be extrapolated to biological fibrillar attachment devices sharing the same geometry.