A Pulsed High-Voltage Generator Utilizing a Monolithic PZT Element and Evaluation of Nonlinear Piezoelectric Behavior in Transient Mode

This paper presents a monolithic pulsed high-voltage (HV) generator utilizing a single piezoelectric element (PZT51 disk, 5 mm in diameter and 740 μm thick) with electrodes series-connected via a flexible polyimide cable. The design, fabrication, assembly, and testing of the HV generator are described. In response to transient mechanical load, the HV generator is evaluated within the stress range from 1 to 5 MPa, and the corresponding peak output voltages vary from 100 to 900 V. Performance comparison between single-electrode pair HV generator and three-electrode pair device indicates series-connected electrodes on a monolithic PZT element greatly boost the output voltage under the same mechanical load conditions. In further tests, the generated high-voltage pulses exceed 1.35 kV and are successfully used to initiate microdischarges on monolithically patterned electrodes across a 75 μm air gap. The measured capacitance of the test HV generator is 25 pF and the calculated charge delivered to the terminal electrodes in each discharge is 34 nC. The nonlinear piezoelectric property of the PZT51 in transient mode is studied. We experimentally obtain a linear increase of the effective piezoelectric coefficient as the applied pressure increases within the range from 1 to 5 MPa. [2012-0356].