Development and Dynamic Modeling of a New Hybrid Thermopiezoelectric Microactuator

This paper presents a new hybrid microactuator based on the combination of piezoelectric and thermal effects. The proposed actuator can perform both a high-stroke coarse positioning through the thermal actuation and a high-resolution fine positioning through the piezoelectric actuation. The microactuator structure is a unimorph piezoelectric cantilever, which also constitutes a thermal bimorph that is very sensitive to temperature variation. While electrical voltage is used to control the piezoelectric actuation, we use a Peltier module to provide the temperature variation and to control the thermal functioning. In order to understand the behavior of the hybrid actuator, a model is developed. For better precision, but at the same time for model simplicity, the thermal part is modeled with the thermal network, whereas the Prandtl-Ishlinskii (PI) hysteresis approach is used to model the nonlinearity of the piezoelectric part. Finally, a series of experimental results validate the developed model.