Physik Instrumente (PI) is expanding the capabilities of its Bi-Phase Inertia Drive (BIX) technology with new motor architectures designed for compact, high-precision nanopositioning applications
Expanding on the technology behind the B-421 BIX nanopositioning stages, PI engineers have demonstrated new developments for higher-force linear motion, rotary positioning, micrometre screw drives, tip/tilt motion, and cryogenic environments.
PI’s B-421 BIX miniaturised piezo stages provide 10nm positioning resolution in a compact package. X, XY, XZ, and XYZ combinations are available, with travel ranges from 13mm to 33mm.
BIX bi-phase positioning stages are based on the stick-slip principle used in piezo inertia motors and employ two synchronised multilayer piezo actuators. The PICMA actuators are driven by mirrored sawtooth signals: one actuator expands while the other contracts, and their combined motion reduces piezo hysteresis and increases acceleration at the friction contact point.
This results in a compact drive architecture that provides precise, repeatable motion while maintaining the self-locking characteristics of piezo inertia motors. The B-421 BIX miniature linear stages can provide 10nm minium incremental motion, 6nm encoder resolution, travel ranges from 13mm to 33mm, and velocities up to 14mm/s. Additionally, the stages can be combined into multi-axis configurations for space-constrained OEM systems.
PI’s BIX development work demonstrates how the same bi-phase drive principle can be adapted to different mechanical architectures and performance requirements.
- High-force BIX uses a two-sided stator with two friction contacts to approximately double the drive force of the standard one-sided design
- BIX micrometre screw drives convert the microscopic motion of the piezo actuators into rotation of a drive screw, reducing friction losses and increasing available force compared to conventional inertia screw-drive mechanisms.
- 2D-BIX combines four PICMA piezo stacks with a lever structure to produce two-axis motion. The concept has been demonstrated in a mirror tip/tilt platform and can operate in both stepping and analogue modes.
- Rotary BIX uses dual-sided stators to drive miniature rotary platforms, extending the technology to compact rotational positioning applications.
BIX designs have been adapted for cryogenic operation, including a flexure-guided linear stage prototype. These developments demonstrate the potential to scale the BIX architecture across different motion requirements while retaining the advantage of the bi-phase drive principle.
For OEM customers, the technology provides a platform for compact, high-precision positioning mechanisms where conventional motorised stage designs may be constrained by available space, holding requirements, or mechanical complexity.
