August 6, 2013 - PI updates N-725 Optical Axis Nanopositioning System for high precision positioning of microscope objectives along the optical axis. While piezo actuation has always been the undisputed choice in optical positioning when dynamics and accuracy matter most, some applications could have benefitted from more travel range. PI (Physik Instrumente) now extends the positioning range to 2 mm while maintaining very short settling times on the order of 20 milliseconds.
Based on a piezowalk motor, the N-725 provides travel ranges of up to 2 mm along the optical axis to quickly and precisely change the focal plane. Despite its small size, the device replaces and combines the performance of two individual stages: a fine focus piezo drive and a stepper motor positioner for coarse, long travel motion. The challenge was to implement the high-stiffness piezo motor in a compact mechanical housing no larger than PI’s previous piezo-flexure-actuator based PIFOC objective stages providing travel ranges from 0.1 to 0.4 mm.
The long-travel piezo motor provides 5 to 20 times the travel range, sub-nanometer resolution and locks into a position, without further need for power, significantly improving long term stability. Optical metrology, super-resolution microscopy and other techniques require the nanometer and sub-nanometer level resolution and millisecond response provided by piezo nanopositioning devices. Until now, travel ranges of a few 100 microns were available, enough for most microscopy applications. PI’s drive principle, based on a coordinated motion of multiple piezo elements, overcomes these limitations. Deep penetration microscopy methods, such as two-photon microscopy, benefit from the new piezo positioning device.
High resolution microscopy methods, such as two-photon microscopy, make it possible to record 3D stacks with up to 1 mm depth in biological samples. Here conventional piezo techniques have posed a limitation. PI’s N-725 piezo-motor objective positioner and scanner breaks with conventional wisdom and helps exploit the new possibilities. The piezo-z-focus drive comes complete with a powerful motion controller and software. It is compatible with leading microscope imaging suite software packages.
About PI
The PI group provides the broadest and deepest portfolio of ultra-precision motion technologies, for markets as diverse as semiconductor manufacturing, bio-technology, photonics, aerospace and medical engineering. PI has 4 decades of experience with the design and manufacture of precision positioning systems based on piezoceramic and electromagnetic drives. The company has been ISO 9001 certified since 1994 and provides innovative, high-quality solutions for OEM and research. PI is present worldwide with 10 subsidiaries, R&D / engineering on 3 continents and total staff of 750+.
