Prediction of Actuation Displacement and Force of a Pre-Stressed Piezoelectric Unimorph, Pumps Considering Internal Stress Effects

Pre-stressed piezoelectric unimorphs are widely used in many engineering field due to their good actuation performances. They are manufactured by using stress mismatch of adjacent layers, which results in the domed shape and internal stress profile of the piezoelectric layer. The internal stress of the piezoelectric layer can affect the actuation performance of the pre-stressed piezoelectric unimorph significantly. This paper investigates the effect of mechanical pre-stress on the piezoelectric actuation characteristics, and evaluated the actuation performance of a new pre-stressed actuator developed by the present authors, PUMPS, considering the internal stress effects.