Linear resonant electrostatic induction motor using electrical resonance with piezoelectric transducers

• Linear electrostatic motor resonating with piezoelectric transducers is proposed.
• Piezoelectric transducers realize high voltage on electrodes and increase force.
• Specific design method of piezoelectric transducers for the motor is described.
• Prototype was constructed with piezoelectric length-extensional bars.
• Step-like motion from non-linear behavior of the piezoelectrics was observed.

This paper proposes an electrostatic linear induction motor resonating electrically with piezoelectric transducers. The motor is based on an electrostatic film motor composed of two thin plastic films containing fine pitch three-phase electrodes, which face each other across a short gap. The motor requires three-phase high voltages on the electrodes in both films to obtain thrust force. Our proposal in this paper is to utilize piezoelectric transducers to realize the high voltage on one of the films: the slider film, by using the transducers as inductive elements that resonate with the electrostatic motor. We describe specific design method of the piezoelectric transducers for this application, and analyze the influences of their properties on the performance of the motor. A working prototype was constructed with piezoelectric length-extensional bars as the transducers. The prototype demonstrated a maximum thrust force of 0.24 N with 500V0-p three-phase excitation. When driven at high voltages, we observed a step-like motion caused by a non-linear behavior of the piezoelectrics, i.e., the jump resonance. The observation indicates a problem in optimal design of the piezoelectric transducers for this specific application.