An ultrasonic motor having a stator and a mobile element made of improved materials. The ultrasonic motor includes an electro-mechanical conversion element, a stator and a mobile element. The electro-mechanical conversion element creates oscillations when an electrical signal is applied to the electro-mechanical...http://www.google.com.au/patents/US5508581?utm_source=gb-gplus-sharePatent US5508581 - Ultrasonic motor with a stator and a mobile element made of improved materials
