Electroadhesion-driven friction enhancement using electret films

Abstract

Friction control has attracted significant attention due to its potential to improve device efficiency and reduce wear. However, achieving rapid, reversible, and robust friction regulation remains a persistent challenge. In this study, we propose a novel strategy for contact control using electret films, which can effectively modulate electroadhesion to enable large-scale friction control. We develop a general model describing the interfacial electro-mechanical coupling mechanism, which is validated through systematic experiments. Both experimental and theoretical results demonstrate that the relationship between the pull-off force and the applied interfacial voltage follows a parabolic curve, with its maxima mainly depending on the charge density, thickness, and dielectric constant of the electret film. With the electret film of about 50 μm in thickness and an applied voltage of approximately 300 V, both the static and dynamic friction coefficients can be increased to more than twice their initial values. This study provides valuable insights into the optimization of mechanical systems in terms of performance enhancement, lifespan extension, energy losses, and thermal management.