Measurement of Charge Separation during Metal-Insulator Friction and Charge Relaxation due to Micro-gap Discharge

Abstract

  We developed an experimental setup to measure in real time the charge generated during friction between a metal and a plastic material in a vacuum chamber in order to reveal the absolute quantity of the initial charge separation in a vacuum and the relaxation processes, e.g., micro-gap discharge, in a gas ambience. In this paper, the static electricity generated by friction between stainless steel or gold metal and polyethylene terephthalate (PET) was measured. The density of the separated charge on the PET-rubbed surface was evaluated. The two-dimensional spatial distribution of light emission from the gas discharge was recorded with a CCD camera, and the voltage of the discharge was estimated.