TWO
MEETINGS AT THE UNIVERSITY AT FAIRBANKS
The Power Problem - Thermoelectric?
While
I was at the University of Alaska, Fairbanks, on February 9th,
Dr. George Happ whom I met in San Diego at the EPSCOR conference,
helped me find the most accomplished 'thermoelectric' and thermodynamics
professor at the college, Dr. Douglas Goering.
It has
been slowly dawning on me, that the biggest challenge we face
developing workable models for wireless data communications
in Alaska, is not getting the radios to work - but delivering
reliable power to them over 6 months, untended, operation.
It is
not just a matter of the cold - down to 60 below zero, which
affects batteries, but also the fact that most data loggers
are in locations in low ground, midst tall trees. Severely limiting
solar panel current production. And there is less wind in central
Alaska that we thought, so even highly efficient wind generators
may not be enough.
We already
have reports from Trout Lake, Wisconsin that the Sieman's solar
panel, Marine West battery arranged failed out on the lake after
only three months of operation in the hard winter. Neither the
panel or the battery performed at their advertised rated power
levels under those conditions. And they are among the best products
on the market.
So I
have started pursuing the question whether or not Thermoelectric
generators, using only the extreme of ambient air temperatures,
and the warmer soil beneath, can generate enough, or supplementary
current.
Dr. Goering
explained to me the issues in Alaska, and that it was not easy
to find such devices that could deliver only milliamps of power.
Larger ones, using natural gas, or even modified to handle propane,
are easier to find. They are both more costly and bigger, and
can be ''overkill' in keeping the low-drawing, sleep-mode radio
batteries supplied with power.
I may
return to him later, and if such devices have to be designed,
his Department could consider doing the engineering.
With
that I left, and started searching for existing companies that
make such devices. So far, at this writing, I have not been
able to find any companies that get down to the milliamp power
production range.
Dr
Goering, Professor of P.E. UAF
A Real Wireless Challenge - Arctic Squirrels
I also
was directed to the offices and lab of Dr. Brian Barnes, of
the Institute of Arctic Biology. Arriving unannounced, he only
had a short time to meet with me, but it was very productive.
Dr.
Barnes manages the Toolik Lake LTER station north of the Arctic
Circle.
Location
of Toolik Research Station
The station
operates, of course, mostly through the summer. And to this
date we understand no researcher stays over the severe winters
(when not much can get done).
The
Station, with the Brooks Range
The
Station in the Summer
Dr. Barnes
has been studying how mammals in Alaska survive the bitter,
prolonged, winter weather. In particular he has studied the
Hibernation of Bears, and Arctic Ground Squirrels that exist
north of the Arctic Circle.
While
I am interested in helping Dr. Barnes link up sensors that he
embeds in the tissue of Brown Bears near the University of Alaska,
wirelessly to the lab, and Internet, I am fascinated with the
challenges posed by the Arctic Ground Squirrels.
Some of the Embedded Devices
Arctic Alaskan Squirrel
For in
the mid 1980's, Dr. Barnes and associates, after trapping 7
males and 5 females, they implanted very small Data Loggers
in their abdomen, which could log their core body temperatures
for 8 months during which the squirrels hibernated in burros
about 1.3 meters deep.
Astonishingly,
these squirrels were capable of letting their core body temperature
fall to ZERO degrees centigrade - freezing point, and even slightly
below. Since their brains cannot stand such conditions for a
prolonged period of time without their neurons and synapses
failing, they automatically let their temperature rise for a
12 or so hour period every two weeks, repeatedly, to the 35
degree centigrade range, during which times the brain would
become active enough to stand a further two weeks of zero degree
torpor. And this cycle repeats itself for all 8 months of arctic
winter, after which they revive, exit their burros and live
another year!
A
Hobo Brand Small Data Logger Used
2
Years of battery life, and 32K of Ram.
Dr. Barnes
wondered whether we could link these loggers inside the squirrels
to a network, wirelessly, and then to the University (and beyond
via the Internet), so in the dead of arctic winter the researchers
could, in real time, follow the progression of the hibernation
of these amazingly adaptable creatures!
Big
challenge, but certainly worth trying.
And
at this point I don't have a clue how to do it.
Previous
Next
