Parallel-Kinematics Flexure Stage (PKFS)

 

This parallel-kinematics flexure stage (PKFS) generates a motion range larger than, or at least comparable to, current commercial designs while simultaneously eliminating the undesired secondary motion associated with them. As opposed to traditional positioning systems, parallel kinematics systems, because of their truss-like structures, are structurally stiffer and lighter and allow for high-bandwidth operations. In addition, errors associated with fabrication tend to cancel rather than compound each other.

These novel stages are able to produce pure translation, eliminating unwanted translations through the innovative coupling of parallelogram four-bar linkage mechanisms. While further reducing the inertia associated with older designs, this design also increases rigidity and stiffness. Finally, the designs facilitate easy and efficient manufacturing. This invention shows potential uses in many diverse fields, from microscopy and medicine to near-field optical sensing, fields of use where the utmost precision, control, and reliability are critical.

This technology is a development in the field of nano-scale positioning stages. The meso-scale, integrated nano-positioning, XY flexure stage can deliver pure translational motion along both the X and Y axes. It accomplishes high motion-resolution while eliminating the troublesome rotational movement often associated with similar devices. Parallel kinematics ensures that the flexure stage does not accumulate errors, but rather it cancels those errors within the kinematic chain.

A flexure stage is a positioning stage in which joints are created by introducing weak or flexible areas in an otherwise rigid structure. Under actuating forces, in this case stimulation, flexing at these weak points causes the stage to move, creating the desired change in position. What makes this technology stand out from the rest is the development of a new parallelogram four-bar linkage structure. This novel design generates the desired movement (or flex), without allowing the stage to rotate, and without sacrificing stability.

As an example of the capabilities of these stages, the XYZ stage is capable of approximately 50 microns of motion along each axis with sub-nanometer resolution, minimum repeatability of 5nm, and a tracking bandwidth of around 100Hz.

Applications:

For the user who demands superior control and stability with a fast response in nano-positioning applications.

  • Microscopy
  • Micro-printing
  • Near-field optical sensing

Benefits

This device provides users with exceptional nano-resolution control of their working stage and offers the pure translational XY and XYZ motion necessary for precision applications.

  • Eliminates undesirable secondary rotational-motion: Stage of positioner will not rotate unpredictably and requires no external corrective devices.
  • Reduces inertia and increases stiffness: Four-bar linkage system increases stability of stage and reduces aberrational, inertial drift.
  • Provides larger work zone: Parallel design offers a larger working stage than that found on other devices with similar resonation frequencies and positioning resolutions.
  • Employs highly linear kinematics: The linear design of this parallel device offers simplicity and stability while increasing user control.