TECH KNOWLEDGEY
EVENTS, ADVANCES, AND NEWS
2009
■ BY JEFF ECKERT
ADVANCED TECHNOLOGY
RECONNECTING
brain and the muscles unimpaired, it
BRAIN CELLS
might be possible to reconnect the
muscles to the motor cortex and let
them start communicating again.
Their study, recently reported in the
journal Nature, indicates that it
could very well work. In research
conducted at the Washington
National Primate Center, they
numbed some monkey’s wrist nerves
with a local anesthetic. The doctors
then provided direct, artificial
stimulation from arbitrarily chosen
motor cortex cells to multiple
muscles. Oddly enough, the monkeys
learned to flex and extend their wrists
to play video games.
Despite the nerve block, the
monkeys were able to control the
contraction strength of their wrist
muscles to match a set of targets on
a computer screen, and they got
better at it as they learned to control
the neurons. The odd thing is that
even neurons usually unrelated to
wrist movement could be used to
control the muscles, which hints that
stroke victims someday may learn to
use undamaged brain areas to restore
lost function.
The study was conducted using
lab instruments, but Fetz and Moritz
also built a portable device from
off-the-shelf components to convert
signals from the motor cortex neuron
cells into stimuli. The matchbox-size
device runs off AA batteries, and
further miniaturization should be
relatively simple. Considerable
refinement is needed, but with
support from the National Institutes
of Health (NIH) Neurology Institute,
the concept looks promising.
PHOTO B Y RENSSELAER/SHAWN LIN.
■ This nanoengineered coating
allows solar panels to absorb the
entire sunlight spectrum.
■ Drs. Moritz (L) and Fetz in their
UW lab.
Let's say you have a toilet that
works fine until the chain that
connects the flush handle to the
flapper breaks. One way to fix it
would be to hook up a motion
sensor and a transmitter to the
handle such that whenever the
system detects movement, it
transmits a signal. This signal is
picked up by a receiver that triggers
a power supply and a solenoid in
the tank which lifts the flapper and
invokes a flush. Or, you could just
replace the chain. Duh!
Now let's say you have a human
being whose leg no longer functions
because of spinal cord damage. One
way to address that is to pick up
some brain waves, decode and
convert the neural signals so they
can be processed by a computer,
and have the computer send signals
to a robotic prosthesis device that
creates the desired movement.
Or, you could just reconnect the
brain and the leg. Duh!
Enter Drs. Eberhard Fetz and
Chet Moritz, both of the University
of Washington (www.washington.
edu), who reasoned that, given that
spinal injuries leave nerve cells in the
12 January 2009
ANOTHER LEAP
TOWARD THE SUN?
One of the obstacles to practical
solar energy is, of course, the
relative inefficiency of the panels. Part
of the problem is that existing panels
absorb only about two thirds of the
sunlight that strikes it, meaning that
about a third of the power potential
slips away unharnessed. However, some
researchers at Rensselaer Polytech
( www.rpi.edu) have demonstrated a
new antireflective coating that allows a
panel to (a) make use of the entire solar
spectrum and (b) gather light evenly
and equally from all angles, thus
eliminating the need to constantly
reposition the panels to track the sun's
position in the sky. The result is an
absorption rate of 96. 21 percent.
According to Prof. Shawn-Yu Lin,
project leader, typical antireflective
coatings are engineered to transmit light
of one particular wavelength. The new
coating stacks seven of these layers
such that each layer enhances the
antireflective properties of the layer
below it. These additional layers also
help to "bend" the flow of sunlight to
an angle that augments the coating's
antireflective properties, so each layer
helps to capture any light that may
have otherwise been reflected off of
the layers below it.
The layers are made up of silicon
dioxide and titanium dioxide nanorods
positioned at an oblique angle so "each
layer looks and functions similar to a
dense forest where sunlight is captured
between the trees."
There was no speculation about
how soon the panels might be
