SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Pastimes : NNBM - SI Branch -- Ignore unavailable to you. Want to Upgrade?


To: lurqer who wrote (24887)3/25/2003 1:40:20 AM
From: abuelita  Respond to of 104155
 
The last line of this post made me smile.

... i wouldn't know -

i didn't drink the water <vbg>

rhoze



To: lurqer who wrote (24887)3/25/2003 7:37:02 AM
From: Clappy  Read Replies (2) | Respond to of 104155
 
We might convert part of the NNBM Bar to a Service Station.

We'll use up the cheap stuff.

-Barkeep

----

Bio-battery runs on shots of vodka


17:48 24 March 03

NewScientist.com news service

An enzyme-catalysed battery has been created that could one
day run cell phones and laptop computers on shots of vodka.

The key to the device is a new polymer that protects the
fragile enzymes used to break down the ethanol fuel,
scientists told the American Chemical Society's annual
meeting in New Orleans on Monday.

Enzyme-based batteries have the potential to be cheaper
than fuel cells that rely on expensive platinum or
ruthenium catalysts. "It sounds great," says Bob Hockaday,
founder of the company Energy Related Devices and designer
of a methanol-powered battery. "Enzymes are inexpensive and
catalytically very active."

Fuel cells work by converting into electricity the energy
released when oxygen and hydrogen react to produce water.
Pure hydrogen is an explosive gas and difficult to store,
so fuel cells often use a chemical source. Ethanol is used
in Minteer's cell, and the enzymes strip off the hydrogen.

But the enzymes are sensitive to slight changes in pH and
temperature and can rapidly degrade and become inactive.
Until now no bio-battery had enzymes that lasted for more
than a few days.

Specially tailored pores

The typical approach to solving this problem has been to
immobilise the enzymes by attaching them to the fuel cell's
electrodes, but they still tend to decay too quickly to be
useful.





So Shelley Minteer and her colleagues at St Louis
University in Missouri coated the electrodes with a polymer
that has specially tailored pores. These maintain a
neutral pH, while being small enough to trap the enzymes
yet big enough to let the alcohol pass through. "The
enzymes have lasted over two months now and they are still
functioning," she says.

Toshiba has just unveiled its first miniature methanol-
powered fuel cell, which promises to keep laptops running
for five hours between re-charging. But Minteer says: "The
main advantage of ethanol over methanol is that it is
simply more readily available. We have actually run our
cells off vodka and gin."

Furthermore, ethanol is more productive with the enzymes
used by Minteer's team and is less toxic. Their bio-
batteries have power densities 32 times greater than those
of other groups, they claim.

However, unlike the Toshiba prototype, the cell is still
too large for portable use. The group is currently working
to shrink the technology, perhaps by tweaking the polymer-
enzyme matrix in order to increase its surface area further.



Celeste Biever, New Orleans