Piezo Technology Tapped To Create New Ultra-Miniature, Virtually-Silent Motors

Said to be virtually silent and one-twelfth the weight and one-fifth the size of standard electromagnetic miniature motors, Elliptec motors use a piezoelectric element to generate high-speed, ultrasonic vibrations of up to 100,000 times/s that, in turn, can spin a wheel or move a rod. They principally produce linear motion at speeds between 0 and 12 in./s and forces up to 1 Newton (e.g., force needed to lift 3 oz.) or higher if several motors are used together. To produce rotational motion, the motor generates linear motion at the rim of a wheel, with the resulting rpm value and torque dependent on the wheel’s diameter. Further, the tiny (about the size of a penny), powerful motors require only a 3V to 6V supply and have only three parts: a piezoelectric element, mounting spring, and vibration frame. And instead of a gearbox, such as is required with dc motors, Elliptec motors use an electric signal to set speed, with the quality of the motor’s motion control reportedly comparable to that of more expensive stepper motors. The new motors are said to be cost-effective alternatives to conventional dc mini motors in applications were they are connected to an integrated circuit or when bi-directional motion is needed, with Elliptec motors requiring less than one-third of the electronic components compared to existing motors. Elliptec motors are expected to find use in scores of products, from toys to track lighting and CD ROM players. For more information on Elliptec motors, contact Guy Pierce at ELLIPTEC AG, a Siemens Corp.’s Technology-To-Business Center LLP start-up, Berkeley, CA. (732) 906-3805.