T. Fuwa, H. Su, R. Yanaka, R. Takase, K. Kobayashi, T. Kawai, K. Sakurai, H. Anzai, S. Kuroda
Gunma University, Japan
pp. 488 - 489
Keywords: electro-rheological effect, electro-friction effect, composite film, semi-conducting particles, polypropylene
Electro-Rheological (ER) fluid is the suspension of polarizable particles in an insulating solvent and has the characteristic that the apparent viscoelasticity changes when an electric field is applied from the outside. This phenomenon is caused by the adsorption of the particles oriented between the electrodes along the electric field direction forming a chain structure or a cluster. This ER effect appears not only in liquid, but also in solid phase. That is, when an electric field is applied on the solid material composed of polarizable particles clusters in insulating matrix, the adsorption occurs between the electrodes and the solid material, which is observed as the change in the friction force. We call this effect “Electro-Friction (EF)” effect. In the present study, a novel EF material is developed by embedding the semi-conducting particles in a solid polypropylene film. When the semiconductor particles reached the percolation threshold, the particles were contacted with each other to a certain extent depending on the content producing the electro-conducting path, which corresponds to the particle cluster in ER fluids, and the composite film exhibited a very strong friction force as much as 18.3 N under an applied voltage of 1300 V.