IEEE Spectrum December, 2007 - 8

NEWS

Briefs

MICROCHIP

moRe RoBoTs ThAn cosTA RicAns

The International Federation of
Robotics gave the latest estimate of
the world's currently operating indus-
trial robot population at a record
951 000. By 2010 that should grow
to 1.173 million. Add to that the total
number of robotic lawn mowers,
vacuum cleaners, and other house-
hold and professional automatons
sold before 2006 (no one knows
how many of these are still in ser-
vice) and you get a robot population
of 4.5 million. If they were a nation
unto themselves, robots would be
just ahead of Costa Rica and behind
Croatia on the population scale.

CARBON NANOTuBES

HEAT SINK

greases	commonly	used	now,	according	to	
IEEE	Fellow	Avram	bar-cohen,	chairman	of	
mechanical	engineering	at	the	University	
of	Maryland,	college	park.	bar-cohen	
says	carbon	nanotubes	show	promise,	
	especially	for	passively	cooled	devices	
such	as	cellphones	and	personal	digital	
assistants,	which	lack	space	for	a	fan.
"obviously,	people	want	more	and	more	
capability	in	these	personal	systems,"	
bar-cohen	says.	"You'd	like	to	run	the	chips	
at	higher	power	and	yet	cool	them	passively."

FLEXIBLE FIT: Carbon nanotubes can channel heat
from a chip into a heat sink but do it best if they
can bend enough to fit into the rough spots on the
heat sink.

According	to	victor	chiriac,	a	principal	
scientist	at	Freescale	Semiconductor	in	
tempe,	Ariz.,	and	an	expert	on	thermal	
management,	the	purdue	team	is	among	
those	leading	the	efforts	to	make	carbon	
nanotube	interfaces	practical.	Among	the	
other	researchers	exploring	the	issue	is	a	
team	at	Stanford	University	that	is	experimenting	with	the	concept	of	growing	tubes	
from	both	sides	of	the	interface	and	joining	
them	in	the	middle.
the	nanotube	research	is	still	far	from	
seeing	use	in	real	products,	though,	chiriac	
says.	"It's	one	thing	to	build	in	a	lab,	and	
another	thing	altogether	to	commercially	
fabricate	a	device,	as	current	costs	could	
be	prohibitive,"	he	says.	He	calls	the	purdue	
group's	ability	to	control	the	diameter,	
length,	and	flexibilities	of	the	tubes	an	
important	step	but	just	one	of	many	that	
need	to	be	taken.		 	 -JoshuA J. RomeRo

Messenger Arrives
At Mercury

satellite to zip by sunburned planet next month
That's one conclusion of the
International Monetary Fund's
October World Economic Outlook.
The bank found that, contrary
to expectation, technological
advances-not the globalization of
trade-were most responsible for the
recent widening of the income gap.
In fact, technology has been the main
force driving inequality since the
early 1980s, says the bank. Rather
than trying to narrow the gap by
stoppering technological progress,
the IMF suggests improving educa-
tion and job training and making it
easier for workers to move from one
economic sector to another.
elecTRic sPin Researchers at the

Delft University of Technology have
managed to control the spin state of
a single electron using only electric
fields. The feat clears the way for
much simpler microchip-based quan-
tum computers. It is easier to gener-
ate an electric field in experimental
quantum computers than to generate
a magnetic field, which scientists have
used to control spin up to this point.
14	

IEEE	Spectrum	|	December	2007	|	NA		

Mercury is getting its first
man-made visitor in more
than 30 years. NASA's
Messenger space probe is
heading for a rendezvous
with the planet, where
sunlight is 11 times as
bright as here on Earth
and temperatures can
swing from a metalmelting 450 º C in the sunlight to lows of -180 º C in the shade.
In the first of several encounters,
Messenger (an acronym for MErcury
Surface, Space ENvironment, GEochemistry,
and Ranging) is scheduled to fly by
Mercury on 14 January 2008 at a little
more than 25 000 kilometers per hour,
coming within 200 km of the planet's
surface. Because it must perform scientific observations and relay them to Earth
while in the scorching glare of Mercury's
tight solar orbit, the craft boasts a multilayer sunshade and the most advanced
communications systems ever deployed
in an interplanetary mission.
Although Mercury is relatively close
to Earth, Messenger is just the second
craft to visit it. Only about 45 percent of

the planet's surface has
been mapped. "We anticipate a flood of data that
will provide new insights
on the origins and evolution of the [inner] planets-including Earth,"
says Ralph L. McNutt Jr.,
the project scientist for
Messenger, which was
designed and built by
the Johns Hopkins University Applied
Physics Laboratory, in Laurel, Md.
The January flyby is only a tease
for what is to come. Messenger is on a
7.9-billion-km trek that is scheduled to
take it around the sun 15 times and past
Earth once, Venus twice, and Mercury
three times, before it finally settles into
an orbit around the sun-blasted innermost planet on 18 March 2011.
To protect Messenger's wiring, electronics, and scientific instruments from
the heat of being within 46 million km
of the sun, it has a highly reflective
and heat-resistant 5-square-meter
micrometeorite-proof sunshade. The
shade is made from alternating layers of
Nextel ceramic cloth (to protect against

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TechnoloGy incReAses inequAliTy
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Table of Contents for the Digital Edition of IEEE Spectrum December, 2007
