Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIST device for detecting subatomic-scale motion may aid robotics, homeland security

19.12.2016

Highly sensitive measuring tool can also be mass-produced

Scientists at the National Institute of Standards and Technology (NIST) have developed a new device that measures the motion of super-tiny particles traversing distances almost unimaginably small--shorter than the diameter of a hydrogen atom, or less than one-millionth the width of a human hair.


Schematic shows laser light interacting with a plasmonic gap resonator, a miniature device designed at NIST to measure with unprecedented precision the nanoscale motions of nanoparticles. An incident laser beam (pink beam at left) strikes the resonator, which consists of two layers of gold separated by an air gap. The top gold layer is embedded in an array of tiny cantilevers (violet)--vibrating devices resembling a miniature diving board. When a cantilever moves, it changes the width of the air gap, which, in turn, changes the intensity of the laser light reflected from the resonator. The modulation of the light reveals the displacement of the tiny cantilever.

Credit: Brian Roxworthy/NIST

Not only can the handheld device sense the atomic-scale motion of its tiny parts with unprecedented precision, but the researchers have devised a method to mass produce the highly sensitive measuring tool.

It's relatively easy to measure small movements of large objects but much more difficult when the moving parts are on the scale of nanometers, or billionths of a meter. The ability to accurately measure tiny displacements of microscopic bodies has applications in sensing trace amounts of hazardous biological or chemical agents, perfecting the movement of miniature robots, accurately deploying airbags and detecting extremely weak sound waves traveling through thin films.

NIST physicists Brian Roxworthy and Vladimir Aksyuk describe their work (link is external) in the Dec. 6, 2016, Nature Communications.

The researchers measured subatomic-scale motion in a gold nanoparticle. They did this by engineering a small air gap, about 15 nanometers in width, between the gold nanoparticle and a gold sheet. This gap is so small that laser light cannot penetrate it.

However, the light energized surface plasmons--the collective, wave-like motion of groups of electrons confined to travel along the boundary between the gold surface and the air.

The researchers exploited the light's wavelength, the distance between successive peaks of the light wave. With the right choice of wavelength, or equivalently, its frequency, the laser light causes plasmons of a particular frequency to oscillate back and forth, or resonate, along the gap, like the reverberations of a plucked guitar string.

Meanwhile, as the nanoparticle moves, it changes the width of the gap and, like tuning a guitar string, changes the frequency at which the plasmons resonate.

The interaction between the laser light and the plasmons is critical for sensing tiny displacements from nanoscale particles, notes Aksyuk. Light can't easily detect the location or motion of an object smaller than the wavelength of the laser, but converting the light to plasmons overcomes this limitation. Because the plasmons are confined to the tiny gap, they are more sensitive than light is for sensing the motion of small objects like the gold nanoparticle.

The amount of laser light reflected back from the plasmon device reveals the width of the gap and the motion of the nanoparticle. Suppose, for example, that the gap changes--due to the motion of the nanoparticle--in such a way that the natural frequency, or resonance, of the plasmons more closely matches the frequency of the laser light. In that case, the plasmons are able to absorb more energy from the laser light, and less light is reflected.

To use this motion-sensing technique in a practical device, Aksyuk and Roxworthy embedded the gold nanoparticle in a microscopic-scale mechanical structure--a vibrating cantilever, sort of a miniature diving board--that was a few micrometers long, made of silicon nitride. Even when they're not set in motion, such devices never sit perfectly still, but vibrate at high frequency, jostled by the random motion of their molecules at room temperature. Even though the amplitude of the vibration was tiny--moving subatomic distances--it was easy to detect with the new plasmonic technique. Similar, though typically larger, mechanical structures are commonly used for both scientific measurements and practical sensors; for example, detecting motion and orientation in cars and smartphones. The NIST scientists hope their new way of measuring motion at the nanoscale will help to further miniaturize and improve performance of many such micromechanical systems.

"This architecture paves the way for advances in nanomechanical sensing," the researchers write. "We can detect tiny motion more locally and precisely with these plasmonic resonators than any other way of doing it," said Aksyuk.

The team's fabrication approach allows production of some 25,000 of the devices on a computer chip, with each device tailored to detect motion according to the needs of the manufacturer.

###

Roxworthy and Aksyuk, the two authors of the new paper, work in NIST's Center for Nanoscale Science and Technology (CNST).

B.J. Roxworthy and V.A. Aksyuk. Nanomechanical motion transduction with a scalable localized gap plasmon architecture. Nature Communications. December 6, 2016. DOI: 10.1038/ncomms13746

Media Contact

Ben Stein
benjamin.stein@nist.gov
301-975-2763

 @usnistgov

http://www.nist.gov 

Ben Stein | EurekAlert!

More articles from Information Technology:

nachricht NASA CubeSat to test miniaturized weather satellite technology
10.11.2017 | NASA/Goddard Space Flight Center

nachricht New approach uses light instead of robots to assemble electronic components
08.11.2017 | The Optical Society

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>