BIO/MEMS/NANO: [Fwd: Viridian Note 00313: Internal Biofuel Cells]

From: Michael M. Butler (butler@comp-lib.org)
Date: Fri May 17 2002 - 07:39:06 MDT


I've wondered about doing this since I was a mere sprout in Ohio.
"You look a little run down, Coppertop." Bruce, as always, comes
up with a snappy capper.

-------- Original Message --------
Subject: Viridian Note 00313: Internal Biofuel Cells
Date: 17 May 2002 05:30:07 -0000
From: Bruce Sterling <bruces@well.com>

Key concepts: fuel cells, glucose, bloodstreams,
injectable mechanisms, alternative power sources

Attention Conservation Notice: Viridian gizmo alert.

(((Tiny, internal fuel cells run off your body chemistry.
Boy, this one is weird. I have no time to comment on this
story at the extensive length it deserves, as I'm leaving
soon for Europe for almost two weeks. But check out those
links.)))

Source: Science magazine
http://www.sciencemag.org/cgi/content/full/296/5571/1223

"TECHNOLOGY:
Biofuel Cells
by Robert F. Service

   "While companies are battling to shrink fuel cells down
to cell phone size, nature has already done them one
better. Enzymes in creatures from bacteria to people
extract energy from compounds such as glucose to power
life. Now researchers are looking to borrow a page from
biology's manual to create rice grain-sized fuel cells
that run on chemicals inside our bodies. (((Aieee!))) Such
cells, they say, could someday power futuristic
implantable sensors that monitor everything from blood
glucose levels in diabetics to chemicals that signal the
onset of heart disease or cancer. (((And why stop there?
Why not power tiny Microsoft X-boxes?)))

    "Researchers can already make glucose-detecting
sensors as small as a millimeter across. 'But you cannot
make a submillimeter-sized battery at a reasonable cost,'
says Adam Heller, a chemical engineer and biofuel cell
pioneer at the University of Texas, Austin. 'That's where
we see the use for miniature biofuel cells.' (((Good
Lord, that's just down the street from the Viridian
Vatican!)))

Links:
http://www.che.utexas.edu/graduate_research/heller.html
http://www.darpa.mil/dso/thrust/md/energy/pa_uta.html

    "Biofuel cells are much further from commercial
development than their larger cousins. (((Whew!))) But
recent progress has been heady. Last August, for example,
Heller and his Texas colleagues reported in the Journal of
the American Chemical Society that they had created a
miniature glucose-powered cell that puts out 600 nanowatts
of power, five times the previous biofuel cell record and
enough to power small silicon-based microelectronics.
Heller's lab has already developed millimeter-sized
glucose sensors, which are currently being commercialized
by a company called TheraSense in Alameda, California. And
the new biofuel cells may one day keep such implantable
sensors running for days to weeks at a time."

Link:
http://www.therasense.com/corporate/faq/futureproducts.html

"Like traditional fuel cells, biofuel cells use catalysts
at two oppositely charged electrodes (...) (((etc etc
etc)))

   "Heller's cells do have their drawbacks. Because
laccase enzymes typically work best in environments much
more acidic than the neutral pH of blood, laccase-based
fuel cells implanted in the body likely wouldn't produce
much power. 'Nature didn't evolve proteins to work with
circuitry,' says Tayhas Palmore, a chemist at Brown
University in Providence, Rhode Island. (((Nice
soundbite, ma'am.)))

http://www.engin.brown.edu/faculty/palmore/

"But Palmore has been working to improve matters here as
well. At a fuel cell conference in Washington, D.C., last
month, Palmore reported that her group had used standard
molecular biology techniques to reengineer the laccase
enzyme so that it retains about 50% of its activity at
physiological pH. And Palmore and her colleagues are now
working on incorporating the reengineered laccase into a
prototype fuel cell that could extract power from
circulating fluids such as blood. (((Including *somebody
else's* blood, presumably.... Maybe you can run your
802.11 network off the glucose-charged bloodstreams of
small, heyperactive, neighborhood children.)))

    "All biofuel cells still face considerable challenges,
however. Most important, blood and other complex bodily
fluids contain numerous compounds that can deactivate or
block the enzymes essential to fuel-cell function, causing
them to stop working within hours or days. But if
researchers can improve their stamina, biofuel cells could
pave the way to a new generation of implanted devices
powered by the body itself."

O=c=O O=c=O O=c=O O=c=O O=c=O
FOR THE BLOOD IS THE VOLTAGE,
AS MY FRIEND RENFIELD ALWAYS
LIKES TO REMARK
O=c=O O=c=O O=c=O O=c=O O=c=O



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