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Device has keen sense for mini-motions

Sandia's motion detector could help predict if earthquakes are coming or if airplane parts are about to rip loose.

Michael Kanellos Staff Writer, CNET News.com
Michael Kanellos is editor at large at CNET News.com, where he covers hardware, research and development, start-ups and the tech industry overseas.
Michael Kanellos
2 min read
Sandia National Laboratories has devised a motion sensor that it says is 1,000 times better than existing technology, a huge leap in performance that could help engineers study earthquakes or improve vehicle design.

The device, which is still in its experimental stages, will allow the naked eye to detect if objects move 10 nanometers. A nanometer is a billionth of a meter. Put another way, that's about nine-thousandths of the width of a human hair, or ordinarily below the level of human sight.

"If you can make very sensitive detectors very cheaply and very small, there are huge applications," Dustin Carr, who led the research team, said in a statement. "Made small, synchronized, cheap and placed on every block, we could take data from all these sensors at once and measure the motion of the earth when there's not an earthquake."

Other uses would be for traction control in cars, automated pilot systems, or sensing if parts are moving on an airplane.

The device, which is made out of silicon, is a microelectricalmechanical system (MEMS). It works by capturing small changes in light patterns. A laser beam shines through two comblike structures in the device. The bottom comb is locked in place, but the top comb is secured by springs.

When vibrations hit, the top comb moves and causes a change in the light pattern. Small disturbances captured by the device create "relatively big" changes in the reflected pattern of the light, making motion detectable, according to Sandia.

The group will discuss the invention more fully at the SPIE Optics East convention in Philadelphia in October.

Large companies and researchers for years have tried to popularize the concept of MEMS, tiny machines crafted out of silicon wafers that can perform like pumps, winches and other machines. Commercially, however, MEMSes have been used only in a few applications, like accelerometers in car air bags. But advances in silicon manufacturing are leading to a new crop of more elegant machines that could find acceptance in the market.

Boston MicroSystems, for example, has developed a MEMS hot plate that can reach 1,100 degrees Celsius in a few seconds.

Pria Diagnostics, meanwhile, has come up with a chip that can analyze body fluids. The company is putting it into a male fertility tester.