Article | July 18, 2022

Objective NanoFocusing Stage Provides 800µm Travel

Shortly after introducing a novel voice-coil motor driven objective Z-focusing stage for auto-focus applications with travel ranges to 7mm, PI now adds a new generation of piezo Z-focus stages for surface metrology and microscopy. The new P-725 PIFOC® piezo focus family is available in 3 travel ranges, 100µm, 400µm and an industry leading 800µm. High performance focusing with nanometer precision is an enabling technology in applications such as super resolution microscopy, wafer metrology, digital pathology and laser material processing. The advanced design makes it possible to provide 800µm travel while maintaining excellent dynamic properties and accuracy. 

A P-725.8, 800µm piezo focus motor mounted on an inverted microscope turret. Matching spacers for identical parfocal length are available for static objectives and the reduced width allows use of directly adjacent lens mounts.

PI’s redesigned focus stages are easier to install, more compact, allowing for multiple units on one microscope turret, and most of all provide higher dynamics, resolution and travel ranges. Equipped with capacitive direct feedback and the award winning, MARS-rover tested PICMA® high-performance piezoelectric actuators the new P-725 nanopositioning stage family also features an improved, and stiffer motion amplifier and flexure guiding system that provides the basis for industry leading step and settle times.  

The new P-725 fast focus motors indicated in green. PI provides a large variety of fast focus drive technologies, each  optimized for different applications:  Direct drive piezo stages provide the fastest response (5 msec), flexure amplified, guided piezo focus stages provide an excellent balance of compactness, travel range, and dynamics, PiezoWalk motors combine piezo precision with compact dimensions and travel ranges to 2mm, and voice coil motors achieve even longer ranges (to 7mm), at slightly reduced dynamics (and compactness). 

High dynamics is especially important in high-throughput automated processes, from Z-stack image acquisition to digital slide scanning and wafer metrology.  The faster an autofocus mechanism can deliver a sharp image, the higher the throughput of the machine that relies on its performance.

Along with the new piezo focus mechanisms, PI also introduces a new compact motion controller and driver unit, the E-709.1C1L. The new digital motion controller provides significantly more current, power, bandwidth and higher sensor resolution, at a lower price than comparable units of the past.