Design And Experiments Of An Ultrasonic Micro-Motor Using A Coil Spring

To realize an effective rotary drive in a narrow interventional medical system, an ultrasonic micromotor using a coil spring is proposed, fabricated, and tested. The proposed motor operates in a first-order bending vibration mode and has a short ineffective section, ensuring sufficient output energy efficiency to enable the rotational motion. Experimental results show that the motor can afford sufficient energy efficiency with vibration frequencies of 52.81 and 52.56 kHz, respectively. The pre-pressure of the motor can be linearly changed with the spring rotor stretching, and no additional pre-pressure mechanism is required to reduce the ineffective section of the motor. Moreover, a maximum speed of 17.8 revolutions/s is achieved with a pre-pressure of 0.6 N. This novel motor holds great promise for numerous potential applications in interventional medical systems.