Objective scanner with piezo stepping drive for 3D Stacks

PI (Physik Instrumente) have developed the new N-725 PIFOC objective scanner with piezo stepping drives especially for positioning microscopy objectives. The N-725 provides travel ranges of up to 2mm along the optical axis. At the same time the technology allows rapid positioning: the new focusing system achieves settling times of around 20 milliseconds for 3 ¼m steps. It has a compact design and is no larger than conventional, piezo-based PIFOC objective stages. The focal plane can easily be changed with a single mechanical system thanks to the combination of high resolution and long travel ranges. Therefore, there is often no need for a combined Zpositioning of the objective, e.g. with stepper motor and additional piezo stages.

The NEXACT piezo stepping drive advantageously combines the best characteristics of piezomotor principles in a compact unit: high resolution, high force and high speed. The feed motion is achieved solely via the nanometre-accurate motion of clamped piezo actuators - wear free, high resolution and with controllable speed. In stepping mode, high positional resolution and high drive force can be achieved over the full travel range. Additionally, the high stiffness allows fast oscillations of 7 micrometer amplitude and resolutions to 30 pm (analogue operation, open-loop).

At the target position, the drive is self-locking, requires no current and consequently generates no heat. The position is stable in the nanometre range so there is no jitter about the target position.

For further information about the N-725 PIFOC objective scanner with piezo stepping drives, please go to www.pi.ws.