Building small motors out of magnets, coils, and solenoids is difficult and expensive, and the resulting motors are not that powerful, precise or efficient.
A new type of motor, the Squiggle motor from New Scale Technologies Inc., Victor, N.Y. (www.newscaletech.com), gives engineers a more precise, faster, and efficient alternative that is comprised of just a few parts. The motor uses a piezoelectric ceramic actuator supporting two threaded nuts holding a threaded shaft. Electrical signals cause the actuator to vibrate ultrasonically and this rotates and moves the shaft back and forth. A demonstration model, the SQ-1000, is cylinder measuring 0.29 in. in diameter and 0.81 in. long. Stall force is 5 N, resolution is better than 100 nm, without encoders, and start/stop times are 200 msec. Speeds range from 1
m m to 2.5 mm/sec, and the threaded shaft can move up to 50 mm. The motor runs on 24 Vdc, and needs less than 200 mA, with an output frequency of about 40 kHz.