A research on the piezoelectric vibration actuator for mobile phone

The authors study the PZT-based composition for a piezoelectric vibration actuator. Specimens of piezoelectric ceramics are produced by the columbite method. The piezoelectric vibration actuator by this composition is designed by ATILA (Magsoft) program using FEM (finite element method). The vibration motor used for a mobile phone must be driven in the frequency of 130 ∼ 200 Hz, so the resonant frequency of piezoelectricity must adjust driven frequency bandwidth. The result of a analysis by ATILA appears to be a dependant property of length, width, thickness and dummy weight about resonant frequency of the piezoelectric vibration actuator. The size of manufactured actuator is 28 x 12 x 0.3 mm³ (length x width x thickness) and this is bimorph type. The test of manufactured piezoelectric vibration actuator measures displacement, acceleration and power dissipation. The piezoelectric vibration device has the more advantage more than electro-magnetic motor, however, the size of manufactured device is larger than electro-magnetic motor.