X7R dielectric multilayer ceramic capacitors show good micro-actuating properties with little hysteresis

The possibility of a kind of industrial-grade X7R type multilayer ceramic capacitor used as an actuator is studied. By applying a DC bias voltage, the ceramic capacitors exhibit a large converse piezoelectric effect which can be used for actuating applications. The experiments show that the capacitor´s thickness changes rather linearly with a voltage applied on it. Three multilayer ceramic capacitors were selected to be studied. A hysteresis <;1.8% and a nonlinearity <;2.0% between the displacement and the driving voltage were observed for a 10 μF capacitor over a frequency range of 0.1-20 Hz and a temperature range of 15-35°C.