A batch fabricated biomimetic dry adhesive

The fine hair adhesive system found in nature is capable of reversibly adhering to just about an ys urface. This dry adhesive, best demonstrated in the pad of the gecko, makes use of a multilevel conformal structure to greatly increase inelastic surface contact, enhancing short range interactions and producing significant amounts of attractiv ef orces. Recent work has attempted to reproduce and test the terminal submicrometre 'hairs' of the system. Here we report the first batch fabricated multi-scale conformal system to mimic nature's dry adhesive. The approach makes use of massively parallel MEMS processing technology to produce 20-150 µm platforms, supported by single slender pillars, and coated with ∼2 µ ml ong, ∼200 nm diameter, organic looking polymer nanorods, or 'organorods'. To characterize the structures a new mesoscale nanoindenter adhesion test technique has been developed. Experiments indicate significantly improved adhesion with the multiscale system. Additional processing caused a hydrophilic to hydrophobic transformation of the surface and testing indicated further improvement in adhesion. (Some figures in this article are in colour only in the electronic version)

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