Ultrafast Displacement Actuation of Piezoelectric Stacks With Time-Sequence

Abstract

Driving a piezoelectric stack with fast response and high output force is critical for its application. A novel ultrafast time-sequence driving method for piezoelectric stacks that could be used in fuel injectors is described and demonstrated. This technique is shown capable of reducing the response time of a piezoelectric stack by considering the stress wave propagating in the stack. Stress wave propagation in a piezoelectric stack is analyzed, and a time-sequence circuit is specially designed to generate driving signals. A piezoelectric stack with 14 layers is fabricated and tested with traditional and time-sequence driving methods. Experimental results show that a linear superposition of stress generated by each piezoelectric layer is obtained and the response speed of the piezoelectric stack is more than doubled. Besides, the generated instantaneous force is also improved considerably.