Office of Technology Transfer – University of Michigan

A Micromachined Pump for On-Chip Vacuum

Technology #2503

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Shamus P. McNamara
Managed By
Joohee Kim
Licensing Specialist, Physical Sciences & Engineering 734-764-8202
Patent Protection
US Patent Pending
On-chip vacuum generated by a micromachined Knudsen pump
J. Microelectromech. Syst., Volume 14. Page 741. 2005


There is growing interest in relying on micromachined systems for gas-handling applications. Current limitations to the adoption of this technology stem from device operation at high temperatures, thus requiring thermal isolation in addition to vacuum-sealed lead transfer and low parasitic capacitance.


Researchers at the University of Michigan have developed improved micromachined devices including a packaged micromachined pump for on-chip vacuum. The device has attained evacuation of a cavity to 0.46 atm using 80mW input power, while maintaining high thermal isolation between a polysilicon heater of the pump and the rest of the device.

Applications and Advantages


  • Actuation of gases for gas chromatography,-nl-spectroscopy, microplasma manufacturing.
  • Pneumatic actuation of liquids for lab-on-a-chip-nl-and chemical sensing devices.
  • Vacuum encapsulation.


  • Can be scaled down to small dimensions,-nl-durability and simplified packaging.
  • Improved efficiency, ability to operate-nl-at high temperature.