Magnetic Nanopositioners

Technology #12082

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Inventors
Professor David Trumper
Department of Mechanical Engineering, MIT
External Link (pmc.mit.edu)
David Cuff
Department of Mechanical Engineering, MIT
Managed By
Christopher Noble
MIT Technology Licensing Officer - Clean and Renewable Energy
Patent Protection

Magnetic Micropositioner and Method of Providing the Same

US Patent 7,765,905

Applications

Micro- and Nanopositioners are used for precision machining tools such as lathes, drill presses, and milling machines.

Problem Addressed

A fast tool servo is a device that can be added to a machine tool to provide an additional axis of motion between the cutting tool and a workpiece. Current fast tool servo technology does not support sufficient bandwidth to meet certain manufacturing goals, and is also not sufficiently fast to machine certain types of materials, for example, plastics. This nanopositioner is a high bandwidth rotary fast tool servo, which provides tool motion in a direction nominally parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece.

Technology

The nanopositioner contains an outer magnetic pole-piece and an inner magnetic pole-piece located within the outer magnetic pole-piece. A permanent magnet and a coil are located between the inner magnetic pole-piece and the outer magnetic pole-piece, wherein the coil is capable of directing magnetic flux between the inner magnetic pole-piece and the outer magnetic pole-piece. An outer movable shell is also movably connected to the outer magnetic pole-piece. The differential screw assembly together with the flexure hinge provide accurate cutting tool positioning in a direction nominally tangent to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece and nominally parallel to the axis of rotation of the swing arm assembly by enabling the upper portion of the base to be repositioned in a fine-grained manner with respect to the lower portion of the base.

Advantages

  • Increases precision of positioning
  • Increases machine speed