With the U-521, PI (Physik Instrumente), has now added a compact linear stage to its portfolio with dimensions of 35 × 35 × 15 mm, similar to the size of a matchbox. The compact design allows easy integration, even when space is limited. In addition to the high speed up to 200 mm/sec, the low inertia (direct drive with no rotating parts) allows for dynamic start-stop behavior with settling times in the milliseconds. An integrated optical linear encoder provides position feedback with 100-nm resolution. Higher resolution versions are available for OEMs.
The patented drive principle features a compact piezoceramic plate that oscillates at 100s of kHz. Each cycle transfers a nanometric displacement onto a ceramic runner coupled to the moving carriage. No energy is consumed at rest, no heat to be dissipated, and the servo jitter is eliminated.
Two stages can be combined to form an XY-setup with no need for an adapter plate. Also, the linear stage is complemented by a number of miniaturized closed-loop rotary stages with diameters from 20 to 50 mm.
Ultrasonic piezomotors are small and provide motion with high resolution, as well as an extremely wide dynamic range from microns/second to 100’s of millimeters/second. A significant advantage over magnetic drive technologies (such as voice-coils, brushless and 3-phase motors, also offered by PI) is the self-locking principle: once the motor reaches a target position, it acts like a ceramic brake and locks the platform into place providing extreme long term stability at zero driving current and heat generation.
Due to their low power requirements, ultrasonic motors can also be integrated into mobile measuring and medical devices. Typical applications include those in industry and research, for example, automatic micromanipulation, positioning of samples or when adjusting optical components, such as objectives and camera lenses. Vacuum-compatible versions (to 10-6 hPa) are also available.
For more information, visit PI’s page on ultrasonic stages at http://www.pi-usa.us/products/Compact_Positioning_Stages/index.php#Ultrasonic.
Filed Under: Motion Control Tips, Encoders • linear