Linear actuator with resolution in the 10^-9 m range

-- Control Engineering, 2/1/2000

Chatsworth Calif.-Accurate and repeatable position control with 2.5 nanometer (10^-9 m) resolution is claimed for a novel linear actuator from Schaeffer Magnetics Division of Moog Inc. A patented transducer of slotted tubular configuration is key to obtaining linear micro-positioning. The transducer is combined with a rotary motor stage (rugged step motor, accurate leadscrew, and gear reducer) to achieve a compact, robust, and power-efficient package.

Consisting of two separate controllable stages, the device's coarse-stage at the back provides a 10-mm overall stroke. The front fine stage 'allows positioning within a 25-micron range anywhere inside the 10-mm stroke of the coarse stage,' according to the manufacturer. The fine and coarse stages are also available as separate products.

The device has been used with mirror positioning systems as well as satellite- and ground-based telescopes. Operating temperatures span the cryogenic range (from 20 K) to room ambient.