Role of capillary adhesion in the friction peak during the tacky transition

Abstract The friction peak that occurs in tire-road sliding when the contact changes from wet to dry was previously attributed capillary cohesion, van der Waals attraction, and surface roughness, but detailed mechanisms have yet be revealed. In this study, static experiments were conducted using a custom-built situ optical microtribometer, which allowed us investigate evolution of friction, normal load, area between polydimethylsiloxane (PDMS) film silicon nitride ball during water volatilization. coefficient increased by 100%, force dropped 30% relative those condition wet-to-dry transition. experiments, probe indentation depth increased, load decreased ?60% as evaporated. Combining results, we propose large appeared study can combined effects adhesive plowing