Ultrasonic-wave motor

Electromagnetic motors, electrostatic motors and ultrasonic motors all employ electricity. The overwhelming majority of motors are electromagnetic motors. The second most-used motor is the ultrasonic motor. The traveling-wave ultrasonic motor was invented in 1982 by Toshi'iku Sashida. Sashida ran a small factory operation called Shinsei Corporation, which produced lapping machines, which are used to create precise flat surfaces, until 1990, when he began to design and manufacture ultrasonic motors exclusively.
Ultrasonic motors are used as the actuators in MRI devices since they can function under intense magnetic fields while electromagnetic motors cannot. They are also used for precision positioning control in surveying equipment.