DARPA-funded researchers recently demonstrated the world's smallest vacuum pumps. This breakthrough technology may create new national security applications for electronics and sensors that require a vacuum: Highly sensitive gas analyzers that can detect chemical or biological attack, extremely accurate laser-cooled chip-scale atomic clocks, and microscale vacuum tubes.
In 2008, DARPA’s Chip-Scale Vacuum Micro Pumps (CSVMP) program set out to create a new class of ultra-high-performance vacuum micropumps. The program achieved an ultimate goal of a vacuum pressure of 10-6 Torr (1 Torr is 1/760 of 1 atmosphere) for a tiny 1 mm3 compartment with the smallest, most power-efficient pumps ever created.
“The process of creating a vacuum in a room large enough to test a spacecraft, for example, is pretty straightforward,” said Andrei Shkel, DARPA program manager. “A sealed room, a large pump and ample power are all that is needed. That approach does not scale down to microscale vacuum chambers that are slightly larger than a grain of sand. We had to harness new kinds of physics to develop these pumps, requiring precision and miniaturization techniques that have never previously been attempted. The results are now available for future applications in the smallest, most sensitive electronics and sensors.”
The program has reached a successful conclusion, and DARPA researchers at the University of Michigan; Honeywell International, Inc; and the Massachusetts Institute of Technology (MIT) demonstrated their pumps.
Researchers at the University of Michigan developed three different pumps in three different pressure categories. From lowest to highest pressure, the categories are microplasma Penning ion high vacuum, Knudsen mid vacuum, and high-frequency peristaltic rough vacuum pumps. Pictured above is a 24-stage microscale rough pump that uses tiny micromachined hexagonal compartments, where each element of the array is either a pump or a valve.