Nanopositionern

Nanopositioners are precision actuators that deliver extremely small, controlled displacements with nanometer-scale resolution. They enable accurate positioning of micro- or nano-scale objects in fields such as scanning probe microscopy, nanofabrication, and optical alignment. Designs emphasize minimal backlash, drift, and parasitic motion to ensure stable, repeatable positioning.

Most nanopositioners use piezoelectric actuators, typically ceramic PZT elements that produce tiny motions with voltage. To overcome nonlinearity and hysteresis, high-end devices employ closed-loop feedback with capacitive or interferometric sensors for linearization and improved repeatability. Motion is transmitted through flexure mechanisms—monolithic, compliant joints that provide smooth, backlash-free translation or tilt without traditional bearings.

Configurations range from single-axis stages to multi-axis stacks and 2D/3D platforms. Common designs include stacked or cross-roller flexure stages and parallel kinematic arrangements. Some systems are optimized for vacuum or cleanroom use, while others prioritize compact form factors for integration into microscopes or optical setups.

Performance is described by travel range, resolution, repeatability, and bandwidth. Resolutions reach sub-nanometer levels, with typical travel in the tens of micrometers for high-precision units; larger stages offer greater travel at the cost of stiffness. Closed-loop control and temperature compensation help maintain accuracy in varying conditions.

Common applications are scanning probe microscopy, nano-assembly, nano-lithography, and precision optical alignment. Limitations include limited travel for ultra-high-stiff systems, nonlinearity and hysteresis in piezo actuators, and sensitivity to temperature and vacuum conditions in specialized environments.