Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Motion Detector 1,000 Times More Sensitive than Any Known

30.09.2004


A new class of very small handheld devices can detect motion a thousand times more subtly than any tool known.



"There was nothing in the [optics] literature to predict that this would happen," says Sandia National Laboratories researcher Dustin Carr of his group’s device, which reflects a bright light from a very small moving object.

Sandia is a National Nuclear Security Administration laboratory.


Carr, who earlier gained fame as a graduate student at Cornell for his creation of a nanoguitar, was selected this week by MIT’s science magazine Technology Review as one of the year’s top 100 researchers under the age of 35. The patent-applied-for device will be the subject of an invited talk at the SPIE Optics East convention in Philadelphia in October, delivered by Sandia team member Bianca Keeler.

Like shadow pictures projected onto a wall by shining light through the fingers of one hand moving over the fingers of the other, the relatively simple measuring device depends upon a formerly unrecognized property of optics: light diffracted from very small gratings that move very small lateral distances undergoes a relatively big, and thus easily measurable, change in reflection. A motion of 10 nanometers can be seen by the naked eye, says Carr. A nanometer is one-thousandth of a micron, which is one millionth of a meter.

As for the device, size matters and small is crucial. "In standard MEMS [microelectromechanical] applications, though the devices are small, very few things that sell are dominated by a search for further miniaturization. There’s not a motivation in MEMS to make things still smaller as a matter of cost. Economics of scale for integrated circuits just don’t apply to MEMS. But our device couldn’t exist unless you made it this small," he says. Features are in the 100-200 nanometer range, with 300 nm between top and bottom combs and 600 to 900 nm between comb teeth. Sub-wavelength interference effects cause the visual display. "Making use of the effect is fairly obvious once you realize it happens," he says.

Fabricated out of polysilicon by standard lithography techniques like those used to make MEMS devices, the Sandia system uses two tiny comb-like structures (instead of fingers) laid one over each other. The bottom comb is locked rigidly in place. The top comb is secured only by horizontal springs. Any tiny motion sends the top comb skittering over the bottom comb, laterally deforming the grating. A very tiny disturbance changes by an unexpectedly large amount the amplitude of light - in the visible to near-infrared range - diffracted from a tiny laser beam shining upon the apparatus.

The measuring device, still in the laboratory stage, is in effect a kind of accelerometer, about the size of the inexpensive microelectromechanical devices that open automobile air bags. Fabricated by the same processes that mass-produce silicon computer chips, the device has multiple possible uses.

"If you can make very sensitive detectors very cheaply and very small, there are huge applications," says Carr. "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. So we could learn what leads up to one."

Another use would be for skid and traction control in cars, detecting if the back end of the car is moving in a different direction from the front end. "Such devices also could take the place of inertial navigation systems," Carr says. These typically require large gyroscopes to keep commercial airplanes moving on a preset course. "We could have handheld-sized devices on Volkswagens that would work even in a tunnel." Other defense applications are possible, he says. He sees a time frame of three to five years before the devices are available for use.

Says James Walker, former Director of Advanced Technologies at Tellium, Inc., former manager of the MEMS Network Element Sub-systems Group at Lucent, Bell Laboratories, and now an independent consultant and patent agent, "To my understanding, it is the first time anyone has tried to manipulate the optical near-field region in order to affect changes to the far-field characteristics of a grating. The ability to do this is a direct result of the nano-scale nature of the device. Due to its high responsivity-to-displacement ratio, I see it having significant, far-reaching application in areas as diverse as chemical sensing, infrared imaging, accelerometry, and displays."

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.

| newswise
Further information:
http://www.sandia.gov

More articles from Physics and Astronomy:

nachricht APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie

nachricht First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>