Abstract:

The authors observed the microstructure of wild grass leaf by scanning electron microscopy and found there were different periodic ratchetstructure arrangements and the ratchetstructure could be oriented in a certain direction. We studied the onedimensional contrast friction between the water drop and surface interface of leaf via the drop moved along the contrasting directions. This investigation indicates onedimensional contrast friction can be generated due to the different threephase contact line resulted from the oriented ratchetstructure at the moment of drop moving along the contrasting directions. It demonstrates thereby the important relationship between microstructure and friction.

Key words: asymmetric, wettability, friction, microstructure