Microscope Stages feature capacitive feedback.
Press Release Summary:

Available in XY and XYZ models with 200 µm travel/axis, PInano(TM) Superresolution Microscope Stages feature direct-measuring capacitive sensors, which offer long-term stability and minimal sensitivity to noise due to high-frequency measurement principle. Bottom mount slide allows full turret rotation while protecting objectives. Additional features include ceramic encapsulated piezo drives and 24-bit controller with USB, Ethernet, and RS-232 interfaces.
Original Press Release:
SR Microscope Stages are More Stable with Capacitive Feedback
Auburn, MA - PI (Physik Instrumente) LP has added two higher-performance models to its successful PInano(TM) superresolution (SR) microscope stage series.
Higher Stability and Reduced Noise with Capacitive Sensors, Lower Cost Piezoresistive Models Still Available
The new models are equipped with direct-measuring capacitive sensors. This type of sensor can provide higher linearity and long term stability than the lower cost piezoresistive sensor-equipped stages which are still available. Capacitive sensors are also less sensitive to noise due to a high-frequency measurement principle as opposed to the DC-based sensing technique used in piezoresistive sensors. The net effect is similar to the higher quality and lower noise on FM radio channels compared to AM radio.
Bottom Mount Slide Allows Full Turret Rotation, Protects Objectives
The large aperture accommodates microscopy accessories such as slide holders, Petri dish holders, etc. The recessed bottom slide mount allows full rotation of the turret without in and out Z-motion, protecting valuable objectives from crashing into the stage on turret rotation.
XY and XYZ Models, 200µm Travel / Axis
Both XY and XYZ stages are available. The low profile design of 20 mm (0.8") facilitates the integration into inverted microscopes from the four major manufacturers Leica, Nikon, Olympus and Zeiss.
Optional Long-Travel Motorized Microscope Stage
An optional 25x25 mm positioning stage with self-clamping ultrasonic ceramic motors serves as a stable basis for the piezo scanning stage and allows imaging of large samples.
Image Acquisition Software
The microscope stages are compatible with all major image acquisition software packages such as Micromanager(TM), Metamorph(TM), etc.
Features & Advantages
Datasheets & More Information:
http://nanopositioning.net/XYZ_nanopositioning_stage.php?#nano