Featured Research

from universities, journals, and other organizations

Cornell Plucks Its Latest Microscopic Stringed Instrument To Study Vibrating Materials At Record High Frequencies

Date:
March 25, 1999
Source:
Cornell University
Summary:
From the folks who brought you the world's smallest guitar, now meet the nanoharp. But while the microsopic guitar made by Cornell University researchers two years ago was just a whimsical demonstration of new nanofabrication technology, this new "stringed instrument" plays the real music of science, serving as a platform to study the physics of very small vibrating systems.

ATLANTA -- From the folks who brought you the world's smallest guitar, now meet the nanoharp.

But while the microsopic guitar made by Cornell University researchers two years ago was just a whimsical demonstration of new nanofabrication technology, this new "stringed instrument" plays the real music of science, serving as a platform to study the physics of very small vibrating systems.

"This is another use for our new ability to make microscopic mechanical systems," said Harold Craighead, Cornell professor of applied and engineering physics, who supervised the research. "By making things very small you bring out properties that aren't evident in larger materials. We can combine this information with other types of measurements made by researchers in materials science to help understand how materials behave. Right now we're working with silicon, but the methods can eventually be applied to other materials."

The new device, carved out of a single crystal of silicon with advanced versions of the methods used to build tiny electronic circuits, consists of two endpieces, one square and one triangular, with several "strings" of varying lengths stretching between them. The strings are actually silicon rods 50 nanometers (nm) in diameter, ranging from about 1000 to 8000 nm long. A nanometer is one billionth of a meter, making each string about 150 atoms thick. The entire device is about the size of a red blood cell.

Dustin Carr, a research support specialist at the Cornell Nanofabrication Facility and a graduate researcher in the Cornell physics department, described the tiny device in a talk, "Nano-Mechanical Resonant Systems in Single-Crystal Silicon," today (March 23) at the 1999 annual meeting of the American Physical Society in the Georgia World Congress Center, Atlanta.

Carr and Craighead work with postdoctoral associate Stephane Evoy, graduate student Lidija Sekaric and Jeevak Parpia, Cornell professor of physics. They built the device using electron-beam lithography and what's called "released silicon" technology, which refers to nanostructures that have been undercut to be freely suspended in space.

The researchers are studying resonance effects in these microscopic systems. In the macroscopic world, plucking a string tuned to middle C, for example, will cause a nearby string tuned an octave higher to vibrate, responding to energy transmitted through the air. Nanodevices operate in a vacuum, but their vibrations can be transmitted through the silicon base.

The researchers make the silicon rods vibrate by applying a radio frequency voltage signal through the silicon base. They then measure the resulting vibrations by bouncing laser light off the strings and observing the reflected light with a sensitive interferometer.

"We've measured the highest frequency man-made vibrating strings, and the smallest vibrating strings, smaller by a factor of four than anyone else has measured," Carr said. "There is lots of interesting behavior that we're still working on trying to understand."

The researchers have measured vibrations at frequencies from 15 Mhz up to 380 Mhz, Carr said." The system can detect a motion of as little as one nanometer, or possibly less."

As with a full-size harp, the resonant frequency at which one of these tiny strings vibrates depends on the length and the mass. However, Carr said, these microscopic strings are not under tension like those in a musical instrument, and the resonant frequency of the nanoharp's strings follows a different rule, varying as the square of the length, like a metal bar struck by a hammer. "It's really more like a xylophone than a harp," he said.

Eventually, Parpia said, the group plans to examine the behavior of these oscillators at very low temperatures. "When you drive a mechanical oscillator, the oscillation increases in amplitude with the amplitude of the drive, but at very low temperatures the relationship becomes non-linear. The intent is to take these very small oscillators and see if they behave differently than the larger devices we've worked with in the past."

The Cornell group is noticing unusual effects in their measuring system, Carr said. "The light intereacts with the system in a very special way. The wavelength of the light we use to measure the vibrations is just a little bit larger than the size of the device. There may be some interesting optical effects," Carr said.

Parpia noted that the measuring system could be turned around, using small oscillators to modulate light. "It could be a very inexpensive way of modulating light with a very narrow frequency range," he said. "Or it could be used as a very good filter to select a particular band of frequencies."

Related World Wide Web sites: The following sites provide additional information on this news release. Some might not be part of the Cornell University community, and Cornell has no control over their content or availability.

--Craighead research group: http://www.hgc.cornell.edu

-- The original Cornell news release on the nanoguitar: http://www.news.cornell.edu/July97/guitar.ltb.html

--American Physical Society 1999 meeting program: http://www.aps.org/meet/CENT99/BAPS/index.html


Story Source:

The above story is based on materials provided by Cornell University. Note: Materials may be edited for content and length.


Cite This Page:

Cornell University. "Cornell Plucks Its Latest Microscopic Stringed Instrument To Study Vibrating Materials At Record High Frequencies." ScienceDaily. ScienceDaily, 25 March 1999. <www.sciencedaily.com/releases/1999/03/990325053349.htm>.
Cornell University. (1999, March 25). Cornell Plucks Its Latest Microscopic Stringed Instrument To Study Vibrating Materials At Record High Frequencies. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/1999/03/990325053349.htm
Cornell University. "Cornell Plucks Its Latest Microscopic Stringed Instrument To Study Vibrating Materials At Record High Frequencies." ScienceDaily. www.sciencedaily.com/releases/1999/03/990325053349.htm (accessed October 22, 2014).

Share This



More Matter & Energy News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
China Airlines Swanky New Plane

China Airlines Swanky New Plane

Buzz60 (Oct. 21, 2014) China Airlines debuted their new Boeing 777, and it's more like a swanky hotel bar than an airplane. Enjoy high-tea, a coffee bar, and a full service bar with cocktails and spirits, and lie-flat in your reclining seats. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins