Optical Trapping and Nanopositioning
Parallel-kinematic piezo flexure stages provide high stability, fast response and nanometer-level motion control for optical tweezers and optical trapping experiments.
Optical trapping, often called optical tweezing, uses a tightly focused laser beam to hold and move microscopic particles, cells, beads, or biological structures without mechanical contact. The light field creates a gradient force that pulls a small dielectric object toward the beam focus, while radiation pressure pushes it along the beam axis. When these forces are balanced, the object is trapped in three dimensions and can be positioned, stretched, or measured with extremely small forces.
Piezo flexure stages are critical in optical trapping because the trap itself is only as useful as the positioning stability around it. Experiments often require nanometer-scale sample motion, smooth scanning, and fast settling with minimal drift. Flexure-guided piezo stages provide frictionless motion, no stick-slip effects, no backlash, and very high repeatability. Their parallel-kinematic designs can also reduce off-axis errors and maintain better orthogonality during XY or XYZ moves.
In optical tweezers, piezo stages are used to position the sample chamber, scan trapped particles relative to optical structures, calibrate force measurements, and apply controlled displacements to biological molecules or microspheres. High bandwidth is important because force, displacement, and dynamic response are often measured in real time. A stable piezo flexure stage improves measurement quality, reduces noise, and makes optical trapping experiments more repeatable.