Micro and nanostructures found on insect wings – designs for minimising adhesion and friction

Abstract

Adhesion and friction have been measured on insect wings where contamination (water and/or contaminating particles) can potentially have a detrimental effect on their flight capabilities or daily functioning. Adhesional forces as low as 2 nN were recorded in air for particles with radii of 10–15 nm, and 20 nN for particles of 31 mm radius. The effective coefficients of friction were in the range of 0.01 to 0.10. The low adhesion and frictional values demonstrate that only very low out-of-plane and in-plane forces are required to remove contaminants of nanometre and micron dimensions from the cuticle membranes.

Many of the surfaces demonstrate superhydrophobic properties and will not only reduce the effects of contact with surfaces but also promote a self-cleaning function for removing foreign bodies. It has also been demonstrated that surface structures and properties can be duplicated on polymer surfaces by using the wing membrane as a 'natural template'.