Tiny Ceramic Linear Motor Moves Fast with Nanometer Precision
23 Sept 2007The novel N-310 NEXACT® PiezoWalk® Linear Motor Actuators are ultra-compact precision drives featuring travel ranges of 20 mm and push/pull forces to 10 N. With their high resolution, NEXACT® drives, are ideal for high-precision positioning over long travel ranges. The N-310 can be operated in open-loop and closed-loop mode (with the addition of an external position sensor). A variety of NEXACT® controllers facilitates the integration into micro- or nanopositioning applications.
NEXACT® is a patented, high-precision linear motor actuator developed to bridge the gap between micro- and nanopositioning devices. At ½ cubic inch and 50 g (1.7 oz), the new NEXACT® actuator is significantly smaller and more cost effective than its big “brother”. This high-force ceramic motor, dubbed NEXLINE® has already won a technology award from the semiconductor community.
NEXACT® actuators provide piezo-class resolution (far below one nanometer) and millisecond responsiveness. The new technology combines virtually unlimited travel ranges with high stiffness in a very small package. In operation, piezoceramic bending elements act on the ceramic runner, connected to the moving part of the application. The length of the runner can be chosen as required. Force capacity, resolution and velocity depend on the piezo geometry and are also scalable. To move the runner over longer distances the stepping mode is used, whereas for distances smaller than 7µm, the linear (sweep) mode enables high-dynamics positioning with resolutions far below one nanometer. The special drive design reduces the operating voltage to 40 V and below.
In contrast to servo or stepper motor actuators, the piezo stepping elements effect linear motion directly, without the need to transform rotation with gears and leadscrews. Backlash and wear are eliminated and the drive is maintenance-free. NEXACT® actuators exhibit high stiffness and are self-locking when powered down with nanometer position stability, and zero dissipation or servo-dither at rest.