Thermo-electro-mechanical synergistic effect on the actuation performance of piezoelectric stack

In a low-temperature environment, the actuation performance of the piezoelectric stack results from the synergic action of the thermo-electro-mechanical field; the actuation performance is influenced by the change in temperature, compressive preload, and excitation voltage. A special and novel instrumentation system is proposed and developed in this study to measure the relationship between the actuation performance of the piezoelectric stack and the change in temperature, preload, and voltage. The bending strain of the cantilever beam driven by the piezoelectric stack reflects its actuation performance, and the corresponding theoretical model is established to optimize the experimental conditions and maximize the strain and signal-to-noise ratio. Based on the experimental results, it can be seen that the actuation performance of the piezoelectric stack increases linearly with the excitation voltage under different temperatures and preload conditions. The static actuation performance increased by 79%-90% when the prestress increased from 0 to 6 MPa, corresponding to a decrease of 15%-30% when the temperature decreased from 20 to -70 °C, and the dynamic actuation performance decreased with an increase in the frequency of the excitation voltage. Consequently, the design methods and ideas are informative to develop an instrumentation system that can measure the influence of thermo-electro-mechanical synergistic effects on the actuation performance of piezoelectric stacks under different temperatures, preloads, and voltages.