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 23, 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 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com
What Is Magic Leap, And Why Is It Worth $500M?

What Is Magic Leap, And Why Is It Worth $500M?

Newsy (Oct. 22, 2014) — Magic Leap isn't publicizing much more than a description of its product, but it’s been enough for Google and others to invest more than $500M. Video provided by Newsy
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