Not a cone in sight
Will this replace the loudspeaker systems we know? Presenting high-fidelity nanotubes:
[R]esearchers from Tsinghua University and Beijing Normal University have demonstrated a radically simpler loudspeaker design based on nanotubes: They showed that a thin film of nanotubes can reproduce sounds over a wide frequency range — including the full human audible range — with high sound pressure level, low total harmonic distortion, and no magnets. The team created the film by drawing nanotubes from a so-called superaligned array grown on a wafer, a technique the group introduced six years ago (see also PHYSICS TODAY, October 2005, page 23). The resulting film, only tens of nanometers thick but up to 10 cm wide, is transparent and has a nearly purely resistive impedance. When electrodes are placed along its ends and an alternating current is applied, the film produces clear tones that can be as loud as a conventional speaker.
And technically, it doesn’t vibrate:
The researchers attribute the sound generation not to vibration but to a thermoacoustic effect first proposed nearly a century ago: Thanks to the nanotube film’s extremely low heat capacity per unit area, changes in the current flowing through the film are reflected in the film’s temperature, and those temperature changes excite pressure waves in the surrounding air.
Will something like this replace my old KLH Thirty-Eights? I hope I’m around to find out.
(Via The Anger of Compassion.)
fillyjonk »
10 November 2008 · 6:42 pm
How long before 20-something men with (apparently) nothing better to do with their time start pumping their cars full of these nanotubes and driving with them full-blast down my street at 2 am?
And can they maybe engineer the nanotubes to go rogue and destroy whatever machinery they’re in if they’re put to that purpose?
sya »
10 November 2008 · 8:57 pm
“And can they maybe engineer the nanotubes to go rogue and destroy whatever machinery they’re in if they’re put to that purpose?”
Well, you could always put the fear of the grey goo in ‘em.
CGHill »
10 November 2008 · 9:05 pm
Now that’s a thought.
WARNING: DO NOT EXCEED 100 dB
You may trigger an uncontrollable replication cycle which will result in the Destruction of the Entire World — STARTING WITH YOUR CAR.
Although you know one of those schmucks will try it anyway.