Pulse voltage operation of two-to-four-phase voltage-induction-type electrostatic motor

Abstract

This paper analyzes pulse voltage operations of a two-to-four phase voltage-induction-type electrostatic motor (VITEM) to clarify the appropriate driving sequences. The paper also evaluates transient charge effects that can possibly enhance the thrust force. VITEM has been studied as a novel centimeter-sized electrostatic film motor whose power to the slider is supplied indirectly through its induction electrodes. Since a smooth synchronous driving was aimed in the past stud- ies, high-frequency AC voltages have been used for the driving. This paper demonstrates that straightforward usage of simple pulse sequences cannot realize continuous stepping driving, and proposes several different sets of modified pulse sequences to realize continuous stepping driving using low-switching-rate pulse voltages. In the experiments, the motor showed continuous stepwise driving with a step width of about half of the electrode pitch. In addition, transient characteristics of charges on films were evaluated experimentally under the pulse driving condition, and contribution for thrust force enhancement was clarified.