The actuator keeps a position with long-term stability and is vibration-proof and shock-resistant. Like the “N-470” open-loop version, the new model achieves its high holding force and resolution by a piezomotor turning a fine pitch screw. The piezomotor drive is self-locking at rest, even when closed-loop control is switched off, and therefore requires no current and generates no heat. It ensures a reliable start-up, even after longer downtimes. The incremental encoder measures the relative motion to a freely definable reference position. In combination with the “E-871” motion controller, the encoder resolution is up to <1 nm. Even with an integrated position sensor, the linear actuator retains a compact design and can be integrated in conventional mirror mounts or stages. – PI offers the closed-loop “N-472” actuator for 7.5 mm and 13 mm travel range with a motion resolution of a few nanometers and excellent repeatability. Optional use in a vacuum down to 10–6 hPa is also possible.