Investigation of Relationship between Electrode Integration Method and Force-to-Volume Ratio in Force Generation System Using Corona Discharge

A force generation mechanism utilizing corona discharge has the advantages of being lightweight, compact, and having no moving parts. The general structure of an electrode used to generate corona discharge is a wire on the high-voltage side and a flat plate on the ground side. To gain greater force generated by corona discharge, it is necessary to install and integrate a large number of electrodes. However, if a large number of electrodes are integrated, the required volume will increase. Therefore, a method of integrating the electrodes to increase the force-to-volume ratio is needed. Therefore, this paper comprehensively examines the two-dimensional arrangement of electrodes on the ground side and investigates the relationship with the force-to-volume ratio. Specifically, the force-to-volume ratio was investigated when the ground side was made of hollow hexagons, squares, or triangles compared to the wire-plate electrode. Also, since it is known that the force is more significant when needles are used on the high-voltage side rather than wires, the high-voltage side was made into a needle for electrodes with hollow polygons. The experimental results show that the force-to-volume ratios of the needle-hollow polygon electrodes were larger when the applied voltage was low, around 20 kV, and that of the wire-plate electrode was larger when the applied voltage was higher than 30 kV. These results show the relationship between the method of integrating the electrodes and the force-to-volume ratio, which was unknown in corona discharge. They can be used as a reference in the design of actuators.