EVENTS, ADVANCES, AND NEWS
■ BY JEFF ECKERT
“MEAT” FOR BRAINS
reasonable to project ahead and imagine
FOR FUTURE ROBOTS?
a robot fitted with a functional brain
that is grown in a lab and made of
“meat” rather than silicon and software.
According to Moses, “We have
been able to enforce simplicity on an
inherently complicated system. Now
we can ask, `What do nerve cells
grown in culture require in order to
be able to carry out complex calculations?’ As we find answers, we get
closer to understanding the conditions
needed for creating a synthetic,
many-neuron `thinking’ apparatus.”
Here philosophy meets science:
Does such a brain actually think? Is it
intelligence or artificial intelligence? Or
artificial artificial intelligence? Is the
robot in which it resides a conscious
being or a lifeless machine? When you’re
done with it, does it go to a scrap dealer
or an old robot’s home? And your
imagination doesn’t have to stop there.
In a seemingly unrelated activity, the
folks at PETA are offering a $1 million
prize to anyone who can grow in vitro
chicken meat and sell it to the public.
(If you think I’m kidding, see www.peta.
So what if Prof. Moses and Perdue
Farms get together and come up with
a boneless chicken breast with a
brain? Is it still ethical to eat it?
PHOTO COURTESY OF WEIZMANN INSTITUTE.
■ Four thresholds, four AND gates,
and a composite diode grown on a
single 13 mm coverslip.
When neurons clump together in
a big enough mass, they can
end up forming a brain, which offers
the ability to think, do arithmetic,
process data, and so on. But if you
pluck one off and drop it into a dish, it
becomes stupid and unable to perform
useful functions (much like what
happens when you separate one
member of a boy band from the
rest). But what happens if you put
them (the neurons, that is) back
together? Could we not assemble a
functional artificial neural network
made up of live neurons? Scientists at
Israel’s Weizmann Institute of Science
( www.weizmann.ac.il) seem to have
proven the affirmative, at least on a
small scale. In an early experiment,
Prof. Elisha Moses and his team created two “wires” made up of about
100 axons each and connected them
to a small number of nerve cells.
When the cells received a signal
along just one of the wires, the result
was uncertain, but when the signal
was carried by both wires, there was
a clear-cut response. Thus, Moses et
al. created a living AND gate.
It’s getting weirder out there.
Further research has produced more
complex functions, so it now seems
In another development sure to stir up
PETA’s ire, Prof. Zhong Lin Wang with
the Georgia Tech School of Materials
Science and Engineering has demonstrated a way to use rodents as a
renewable source of electricity. It appears
that hamsters — being especially
energetic and active — are the prime
candidates. (Predictably, rats turned
out to be less willing to participate.)
The concept is actually applicable
to almost any kind of irregular
12 April 2009
■ This hamster was recruited
to demonstrate conversion of
biomechanical energy to electricity.
mechanical movement, including
finger tapping, a flag flapping in the
breeze, and the vibration of your
vocal cords after an anvil lands on
your foot. In the rodent-based
demonstration, Wang placed a
nanogenerator in a little jacket,
slipped Mr. Hamster into it, and set
him to running in an exercise wheel.
The generator works through the
piezoelectric effect. Zinc oxide wires,
encased in a flexible polymer substrate, are anchored at each end with
an electrical contact plus a Schottky
barrier at one end to control current
flow. Flexing the substrate produces
alternating current, although not very
much of it — four of the generators
produced only 0.5 nA. At that level,
it would take thousands of them to
drive a simple Bluetooth device.
Nevertheless, “We believe this is
the first demonstration of using a live
animal to produce current with nanogenerators,” Wang stated. “This study
shows that we really can harness human
or animal motion to generate current.”
Toward the end of 2008, the
world’s fastest supercomputer
was still the 1.105 petaflop IBM