Synergistic effect of sharkskin-inspired morphologies and surface chemistry on regulating stick-slip friction.

The tribological behaviors of soft materials are closely related to their surface chemistry and morphology. Thus, this study investigates the effects of surface chemistry and morphology on the stick-slip friction of polydimethylsiloxane (PDMS). Air plasma treatment is conducted to modify the surface chemistry, and the bionic shark skin texture is replicated on PDMS. The synergistic effect of the bionic shark skin texture and air plasma treatment on stick-slip friction is evaluated. The results show that air plasma treatment and bionic texture decrease the friction force. Various stick-slip features are observed under different numbers of pendant chains at the contact interfaces, which increase the adhesion force. This study provides fundamental insights into the stick-slip behaviors of other soft materials. [Display omitted] • Stick-slip patterns were proposed to analyze the stick-slip friction behavior of soft material such as PDMS. • Air plasma treatment was used to change surface chemistry of PDMS and decrease the friction of PDMS. • Bionic (shark skin) structure was replicated on PDMS to reduce the friction force and stick-slip effect. • Synergistic effect of surface chemistry and topography on friction of PDMS is analyzed and explained. [ABSTRACT FROM AUTHOR]