Experimental bench for studying the relation between the dynamic characteristics of the frictional motion and the electric potential at the surface of polymer slabs in sliding conformal contact

Quantifying the triboelectric charging that occurs at polymer-on-polymer contact is crucial in the appropriate design of sliding or rolling components of various mechanisms. The paper describes the key devices and instrumentation of a laboratory bench developed for the accurate study of the tribocharging characteristics of polymer slabs in frictional sliding conformal contact. The bench enables the adjustment of several factors that affect the electrostatic charge generation (relative sliding speed, normal contact force, and number of back-and-forth cycles), and is equipped with sensors for the continuous monitoring of sample displacement, as well as of both normal and tangential forces. The triboelectric charge is evaluated by non-contact 2-D mapping of the electric potential at the surface of the samples at the end of the frictional process. The experimental methodology includes appropriate filtering of the signals provided by the sensors, before being recorded and interpreted. The cartography of the surface potential is put in relation with the dynamic characteristics of the frictional motion. The effectiveness of the laboratory bench is illustrated by the study of the electric potential generated by frictional sliding conformal contact between rectangular slabs of Polyvinyl Chloride (PVC) and Acrylonitrile Butadiene Styrene (ABS).