Motor squiggles its way into vacuum applications

The Squiggle ultrasonic linear motor from New Scale Technologies Inc., Victor, N.Y., is a tiny tool for making miniaturized products and nanotechnology research. While electromagnetic actuators have dominated the motion control industry, the Squiggle motor uses piezoelectric ceramics to deliver 20-nm resolution and tens of millimeters of stroke.

Now the company offers a vacuum-compatible version of the motor, called SQ-2000C, for automating critical alignments in high-vacuum instruments — without mechanical feed-throughs or stepper motors. The motor offers small size, nanometer precision, zero magnetic fields, and low outgassing and heating. What's more, it's compatible with vacuum pressures as low as 10-7 Torr. The motor's nanometer positioning is suitable for such applications as semiconductor manufacturing and testing, scanning electron microscopes, and scanning ion mass spectrometers.

Squiggle motors use a piezoceramic tube that supports two threaded nuts that, in turn, hold a threaded shaft. The tube is electrically driven at an ultrasonic frequency that can't be seen or heard. When the tube vibrates (similar to a person trying to keep a Hula-Hoop on their hips) the nuts orbit, and the shaft rotates and translates in and out.