Development of a new type piezoelectric micromotor

To realize miniaturization of actuators, construction of the actuators nece ssitates simple structured components and easy configuration. To satisfy th ese requirements, we devised a piezoelectric micromotor with a simplified a nd flat stator [K. Tani, M. Suzuki, K. Furuta, T. Sakuhara, T. Ataka, Devel opment of a new type piezoelectric micromotor, Proc. 11th IEEE Ann. Int. Wo rkshop on Micro Electro Mechanical Systems (MEMS '98), Heidelberg, Germany, Jan 25-29, 1998, pp. 396-401]. This former micromotor is 2 mm both in diam eter and in height, and generates rotation by micro vibration of the stator . For the former micromotor, we have experimentally confirmed that the rotati onal characteristics correlated with the contact condition between the roto r and the stator, and that the condition was essential to stable rotational characteristics. Therefore, we have devised a new type piezoelectric micro motor with a flat spring that adjusts contact conditions, which structure i s suited for further miniaturization. The new micromotor is 2 mm in diamete r, 0.3 mm in height and the volume is 0.49 mm(3) (which is one seventh of t hat of the former micromotor). The new micromotor stably rotates at any pos ture, and the starting torque is measured at about 3.2 mu Nm. The new type piezoelectric micromotor consists of components whose structur e functions flexibly such as the Smart structure, which is different from t he conventional actuators. In this study, we have achieved a micro-sized mo tor for practical use in micro-mechanism fields. (C) 2000 Elsevier Science B.V. All rights reserved.