A CYLINDRICAL MICRO ULTRASONIC MOTOR USING PZT THIN-FILM DEPOSITED BYSINGLE PROCESS HYDROTHERMAL METHOD (PHI 2.4 MM, L = 10 MM STATOR TRANSDUCER)

micro ultrasonic motor using PZT (lead zirconate titanate) thin film h as been improved by a single process hydrothermal method. The hydrothe rmal method is a unique method for depositing PZT thin film in a solut ion. An earlier reported hydrothermal method consisted of two linked p rocesses. Our new method, however, has only a single process. Hence, l ess distribution of chemical components of the PZT film contributes to a higher efficiency of the stator transducer. The piezoelectric facto r dal was -30 pC/N for this new method, which is six times larger than that of the previous method. The output torque of the micro ultrasoni c motor fabricated by the single process hydrothermal method was measu red. The output torque was 7.0 mu Nm, and the maximum revolution speed was 880 rpm at 15 Vp-p driving voltage.