A new torsional actuator based on shear piezoelectric response

A torsional actuator generating angular displacement from the piezoelectric shear strain was developed. The actuator is a tube consisting of an even number of the segments poled along the length, which are adhesively bonded together, and the joints act as electrodes to apply the driving voltage. The experimental data measured on the prototype actuator: (i) prove the proposed concept of the torsional actuator, (ii) show that the actuator functions well under the torque load, and (iii) demonstrate that it has superior characteristics compared to previously reported designs of torsional actuators. In addition, one of the obvious advantages of the present design of the actuator is its simplicity: the piezoelectric shear strain is transformed directly into the angular displacement, whereas in the previously reported actuators, the conversion mechanism into the torsional motion was rather complicated which thus required a sophisticated design of the whole system.