Biology Talk

Blackwater · Guest

BBC NEWS
http://news.bbc.co.uk/2/hi/technology/6272752.stm

A tiny generator powered by natural vibrations could soon be helping
keep heart pacemakers working.

Created by scientists at the University of Southampton, the generator
has been developed to power devices where replacing batteries is very
difficult.

The device is expected initially to be used to power wireless sensors
on equipment in manufacturing plants.

The generator's creators say the generator is up to 10 times more
efficient than similar devices.

Power packed

The tiny device, which is less than one cubic centimetre in size, uses
vibrations in the world around it to make magnets on a cantilever at
the heart of the device wobble to generate power.

Although the generator produces only microwatts this was more than
enough to power sensors attached to machines in manufacturing plants,
said Dr Steve Beeby, from the University of Southampton, who led
development of the device.

"The big advantage of wireless sensor systems is that by removing
wires and batteries, there is the potential for embedding sensors in
previously inaccessible locations," he said.

Using the tiny generator also made it possible to use larger numbers
of sensors because there was no longer the need to visit them to
replace or recharge batteries, said Dr Beeby.

The generator was developed to sit inside air compressors but, said Dr
Beeby, it could find a future role in self-powered medical implants
such as pacemakers.

In a pacemaker the beating of the human heart would be strong enough
to keep the magnets inside the device wobbling.

It could also be used to power sensors attached to road and rail
bridges to monitor the health of such structures.

Work on the project was funded by the EU as part of the 14.3m euros
(£9.67m) Vibration Energy Scavenging (Vibes) project that is looking
at how to use environmental vibrations to generate power.

*

OK ... why hasn't this been done ALREADY - like a DECADE ago ???
The minute samarium-cobalt and NIB magnets were availible the
old lightbulb should have lit across the globe, especially
with medical techs. Wobble a strong magnet near conductive
coils and you get ELECTRICITY. For pacemakers, brain
stimulators (Parkinsons & other ailments) and automatic
medicine dispensers the amount of electricity needed is
very small. The "wobbler" can keep a super-cap fully charged,
no real high-tech stuff involved. Cheap, efficient, effective.

There's ANOTHER unexploited "free" energy source - the radio
waves which permeate every millimeter of this planet. From
AM broadcasters through Wi-Fi, we're constantly bathed in
RF energy from communications equipment and power lines.

If you're of a certain age, you'll remember those "crystal
radio" kits (pre-fab units were also sold). Essentially
a slug-tunable antenna (occasionally a fine-tuner was
incorporated), a germanium whisker diode and a crystal
earphone. The RF from strong AM stations was half-rectified,
thus demodulated, and the resultant AF was sent to the
earpiece. They were tinny, but loud enough to hear across
the room if you took the earpiece out of your ear.

This represented rather a lot of power (in biological terms
anyway). A power unit can easily be constructed along simiar
lines and you don't even want the tuning circuit. A coil
with an antenna a few feet long, a diode (or more if you
want to salvage the other sideband) and a super-cap. Should
be able to scavenge usable power from 60 Hz hum up into
the VHF band. Scavenging UHF->microwave might require a
second circuit to optimize power capture.

There's plenty OF it, even at the poles or the middle of
the pacific ocean. The only 'dead zone' might be a deep
mine with a lot of iron ore around - but even then it
would get military VLF/ELF transmissions. The whole thing
would be the size of a 1/2-AA battery and weigh a few grams.
The antenna lead, if desireable, could be strung into the
abdominal cavity.

Again, MORE than enough power to run pacemakers and such.
If anything, you'd have to include a zener to clip spikes
cause by nearby lighting and electrically noisy motors.
A completely passive device, no moving parts at all.
Might not work on Mars ... but then nothing's perfect.

Allan Adler · Guest

There was also a recent Science News article on stuff like this. It mentioned
that the idea of scavenging energy goes back at least to the 1920's with
the wristwatch that didn't need to be wound because it derived energy from
the movements of its wearer.
--
Ignorantly,
Allan Adler <ara@zurich.csail.mit.edu>
* Disclaimer: I am a guest and *not* a member of the MIT CSAIL. My actions and
* comments do not reflect in any way on MIT. Also, I am nowhere near Boston.

Blackwater · Guest

On 05 Jul 2007 21:39:16 -0400, Allan Adler <ara@nestle.csail.mit.edu>
wrote: