Three of the 6-axis nanopositioning stages shown here are based on piezo stack/flexure guide mechanisms. The other models are based on crossed-roller bearings and piezo motors, providing longer travel ranges.
Piezo stack/flexure stages are completely free of friction, wear and maintenance and provide very fast response, settling and resolution without backlash and reversal play. However, motion ranges are typically limited to a few 100 microns.
PI offers a large variety of multi-axis piezo stages, most with large apertures for optics applications.