Carbon nanotubes could act as an efficient music speaker
November 3, 2008 by Lisa Zyga
Excerpt from a video of Lin Xiao´s nanotube music speaker. The speaker produces sound when a current passes through, due to a thermoacoustic effect. Credit: Lin Xiao, et al.
(PhysOrg.com) -- While carbon nanotubes are widely praised for their strength and electrical properties, no one has thoroughly investigated their acoustic properties, until now. A team of Chinese researchers has found that zapping sheets of carbon nanotubes with an electric current causes the nanotubes to emit sound.
The team, which consists of scientists Shoushan Fan and colleagues at Tsinghua University in Beijing, China, and Beijing Normal University, hope that the discovery could lead to the development of cheap, flat loudspeakers. Examples of carbon nanotubes´ musical abilities can be heard here and here.
To create the nanotube speaker, the researchers sent an audio frequency current through a thin sheet of carbon nanotubes, generating a sound. Unlike standard loudspeakers that generate sound by vibrations in the surrounding air molecules, the nanotube speaker doesn´t emit vibrations. The team used a laser vibrometer to detect vibrations in the sheet, but found nothing.
Instead, the nanotube speaker likely works as a thermoacoustic device: when an alternating current passes through the sheet, the sheet experiences rapid temperature oscillations alternating between room temperature and 80 °C (176 °F). These temperature oscillations cause pressure oscillations in the surrounding air, producing the sound, while the nanotube sheet remains static. One advantage of this method is that, even if part of the nanotube sheet breaks, it should continue to emit sound, unlike conventional speakers.
This thermoacoustic phenomenon was actually discovered in the late nineteenth century, when scientists passed a current through a thin foil to produce sound, leading to the invention of the "thermophone." Although the principle is the same, however, the nanotube sheet acts much more efficiently than foil because it doesn´t require nearly as much applied heat to increase its temperature. Specifically, the nanotube sheet´s heat capacity is 260 times smaller than platinum foil, making nanotubes 260 times more efficient and able to produce a louder sound.
The Chinese researchers envision several interesting applications for the nanotube speakers. Because the nanotube sheets can be stretched to be visually transparent and still produce sound, they might be fitted over the front of an LCD screen to replace conventional speakers. Another possibility is incorporating the nanotube speakers into textiles to create musical clothes.
More information: Xiao, Lin, et al. "Flexible, Stretchable, Transparent Carbon Nanotube Thin Film Loudspeakers." ASAP Nano Lett., ASAP Article, 10.1021/nl802750z.
© 2009 PhysOrg.com
-
The right recipe: Engineering research improves laser detectors, batteries
Feb 06, 2012 |
5 / 5 (7) |
0
-
NIST releases first certified reference material for single-wall carbon nanotubes
Dec 21, 2011 |
5 / 5 (2) |
0
-
Graphene foam detects explosives, emissions better than today's gas sensors
Nov 24, 2011 |
3.9 / 5 (8) |
3
-
Carbon nanotube forest camouflages 3-D objects
Nov 21, 2011 |
3.7 / 5 (6) |
5
-
'Mirage-effect' helps researchers hide objects (w/ video)
Oct 04, 2011 |
4.4 / 5 (10) |
9
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (30) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (3) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (1) |
0
-
Rubber production is likely to gradually reduce
2 hours ago
-
Help! Physics Momentum/Impulse problem!
3 hours ago
-
Gauss' law cubes, how to prove
4 hours ago
-
A grandfather pulls his granddaughter, whose mass is 20.5 kg
6 hours ago
-
what is significance of torque
6 hours ago
-
Difference between volume displaced fluid and volume of the object
7 hours ago
- More from Physics Forums - General Physics
More news stories
'Dark plasmons' transmit energy
Microscopic channels of gold nanoparticles have the ability to transmit electromagnetic energy that starts as light and propagates via "dark plasmons," according to researchers at Rice University.
10 hours ago |
5 / 5 (4) |
0
|
Nanotube therapy takes aim at breast cancer stem cells
Wake Forest Baptist Medical Center researchers have again proven that injecting multiwalled carbon nanotubes (MWCNTs) into tumors and heating them with a quick, 30-second laser treatment can kill them.
Nanotechnology / Bio & Medicine
15 hours ago |
5 / 5 (1) |
0
|
Inspired by steel, nanomanufacturing gets wear-resistant carbide tip
(PhysOrg.com) -- Scientists at the University of Pennsylvania, the University of Wisconsin-Madison and IBM Research - Zurich have fabricated an ultrasharp silicon carbide tip possessing such high strength ...
20 hours ago |
5 / 5 (3) |
1
|
New kind of solar cell could capture significantly more energy than current cells
New solar cells could increase the maximum efficiency of solar panels by over 25%, according to scientists from the University of Cambridge.
Feb 08, 2012 |
4.5 / 5 (11) |
14
|
New technology platform for molecule-based electronics
Researchers at the Nano-Science Center at the University of Copenhagen have developed a new nano-technology platform for the development of molecule-based electronic components using the wonder material graphene. At the same ...
Nanotechnology / Nanomaterials
17 hours ago |
5 / 5 (2) |
0
FDA-approved drug rapidly clears amyloid from the brain, reverses Alzheimer's symptoms in mice
Neuroscientists at Case Western Reserve University School of Medicine have made a dramatic breakthrough in their efforts to find a cure for Alzheimer's disease. The researchers' findings, published in the journal Science, show t ...
Hydrogen from acidic water: Researchers develop potential low cost alternative to platinum for splitting water
A technique for creating a new molecule that structurally and chemically replicates the active part of the widely used industrial catalyst molybdenite has been developed by researchers with the Lawrence Berkeley ...
Ultraviolet protection molecule in plants yields its secrets
Lying around in the sun all day is hazardous not just for humans but also for plants, which have no means of escape. Ultraviolet (UV) radiation from the sun can damage proteins and DNA inside cells, leading ...
Soraa LED light may dim 50-watt halogen rivals
(PhysOrg.com) -- Soraa, a Fremont, California company founded in 2008, this week launched its first product, a light that uses LEDS (light emitting diodes). The "Soraa LED MR16 lamp" is the "perfect" replacement ...
Anyone can learn to be more inventive, cognitive researcher says
There will always be a wild and unpredictable quality to creativity and invention, says Anthony McCaffrey, a cognitive psychology researcher at the University of Massachusetts Amherst, because an "Aha moment" is rare and ...
Engineers find inspiration for new materials in Piranha-proof armor
(PhysOrg.com) -- Its a matchup worthy of a late-night cable movie: put a school of starving piranha and a 300-pound fish together, and who comes out the winner?
Nov 03, 2008
Rank: 5 / 5 (1)
Oh yeah, it should change color, display images,compute and glow too !!
Nov 03, 2008
Rank: 5 / 5 (2)
I'm not against the clothes idea, but I can now see us getting entertained continuously by kids turning up the bass on their shorts, instead of hearing it as they pass by in their cars. Thump! Thump! Uh oh, I'm starting to get old... :-(
Nov 03, 2008
Rank: not rated yet
Nov 03, 2008
Rank: not rated yet
We are working towards flexible notebooks and soon maybe solid state speakers. If only we can get rid of the fans.
Nov 03, 2008
Rank: not rated yet
Nov 04, 2008
Rank: not rated yet
I've got my hopes set on thermoelectric cooling devices that recapture the wasteful heat, or better yet, devices with features of "superconductors" that don't produce heat in the first place!
I can dream. :(