Technologies
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WARF: P130168US01

Smoother Surfaces with Pulsed Laser Polishing


INVENTORS -

Frank Pfefferkorn, Xiaochun Li, Neil Duffie, Chao Ma, Venkata Madhukanth Vadali

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a laser polishing technique that varies operating conditions between passes.
OVERVIEWPulsed laser polishing (PLP) helps smooth metal and other material. The technique employs lasers to irradiate a surface, melting small areas with each pulse. In these molten areas, rough surface protrusions, or asperities, are ‘pulled down’ by surface tension. If this happens before the melt resolidifies, the resulting surface is smoother.

While PLP provides better heat and melt control than other approaches, such as continuous wave (CW) laser polishing, large surface asperities can persist. The method must be improved, especially in the context of microscale devices.
THE INVENTIONUW–Madison researchers have developed a two-regime method to reduce rough surface features using a multiple-pass PLP approach.

In the first regime, melt pools are created on the surface using energy pulses, which generate higher temperatures where the beam is focused. Thermocapillary flow pulls down asperities into the melt pools. This can cause material to push up at the edge of the pools as they resolidify. A second regime applies different energy pulses to remove and/or rearrange the upwelled material.
APPLICATIONS
  • Polishing metallic parts
  • Creating mirror finishes
  • Microfabricated and micromanufactured parts, particularly for biomedical applications
  • Useful for tool and die makers, including plastic injection molders and optical part manufacturers
KEY BENEFITS
  • Smoother surfaces
  • No debris
  • No change in the dimensional form
  • Much easier to polish features with tight dimensional tolerances
  • Enables very fast selective polishing
  • Can polish microscale features and parts
  • Reduces height of high- and low-frequency surface asperities
STAGE OF DEVELOPMENTExperimental results on micro end-milled titanium indicate greater than 70 percent improvement in surface finish can be achieved.
Contact Information
For current licensing status, please contact Emily Bauer at emily@warf.org or 608-960-9842.
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Since its founding in 1925 as the patenting and licensing organization for the University of Wisconsin-Madison, WARF has been working with business and industry to transform university research into products that benefit society. WARF intellectual property managers and licensing staff members are leaders in the field of university-based technology transfer. They are familiar with the intricacies of patenting, have worked with researchers in relevant disciplines, understand industries and markets, and have negotiated innovative licensing strategies to meet the individual needs of business clients.