An impact rotary motor based on a fiber torsional piezoelectric actuator.

A prototype small impact rotary motor has been fabricated based on a newly developed torsional actuator which is 15.0 mm long and 1.0 mm in diameter. The motor can rotate when it is powered with a saw-shaped voltage. The experimental results show that its angular speed is proportional to both the driving voltage's amplitude and the frequency under 1 kHz. The large nonlinearity occurs at higher driving frequency due to the resonance of the partial mechanical structure of the motor. The motor can rotate at a speed of 90 rpm with a saw-shaped driving voltage of 600 V(p.-p.) at 8 kHz, and produce a stall torque of 80 microN m with 1000 V(p.-p.) at 3 kHz.