Investigations of electronic amplifiers supplying a piezobimorph actuator

• The theoretical and simulation model of piezobimorph actuator dynamics is proposed and implemented in MATLAB-Simulink software.
• The paper presents the two amplifiers that were designed and built: one based on a high-voltage operational amplifier and one based on an audio amplifier.
• The simulation results are presented and compared with investigation results.
• The influences of amplifier output current limitation are tested.
• The investigation results have shown that the low cost audio amplifier can be successfully used for supply and control of piezobender actuator.

Piezoelectric bending actuators, also known as bimorphs, are characterized by very good dynamic properties and by displacements in a range of a few millimeters. Therefore these actuators are used in a wide range of applications. However their usage is limited because they require supplying amplifiers with output voltage of about 200 V, which are rather expensive. This paper presents investigation results of such amplifiers with high voltage output. The model of a piezobending actuator is proposed and implemented in Matlab-Simulink software in order to simulate the behavior of the actuator supplied by the amplifiers. The simulation results are presented and compared with investigation results of high voltage amplifier used for supplying a piezoactuator. The influence of current limitation of operational amplifier on the actuator current is tested. Finally, a low cost audio power amplifier is proposed to control the piezobender actuator (as a cheaper alternative to the high-voltage amplifier) and its investigations results are presented in the paper.