TIME: Almanac 1990/1990 Time Magazine Compact Almanac, The (1991)(Time).iso/time/112089/11208900.077

Text File | 1990-09-19 | 10KB | 179 lines

TECHNOLOGY, Page 108

The Incredible Shrinking Machine

Breakthroughs in miniaturization could lead to robots the size

of a flea

By Philip Elmer-Dewitt


    To the naked eye, the object mounted on a postage stamp-size
wafer and held aloft by a pair of tweezers is all but invisible.
Even under a bright light, it looks like nothing more than a speck
of dust. But magnified 160 times in an electron microscope, the
speck begins to take on shape and function: a tiny gear with teeth
the size of blood cells. "You have to be careful when handling
these things," warns Kaigham Gabriel, an engineer at AT&T Bell
Laboratories. "I've accidentally inhaled a few right into my
lungs."

    The miniaturization of technology, having made extraordinary
progress in the 40 years since the invention of the transistor, is
about to make another shrinking leap. Adapting the chipmaking
equipment used to squeeze millions of electrical circuits onto
slivers of silicon, researchers are creating a lilliputian tool
chest of tiny moving parts: valves, gears, springs, levers, lenses
and ball bearings. One team at the University of California,
Berkeley, has already built a silicon motor not much wider than an
eyelash that can rotate 500 times a minute.

    Welcome to the world of microtechnology, where machines the
size of sand grains are harnessed to do useful work. Huge numbers
of microscopic sensors are already employed to measure the
temperature, air pressure and acceleration of airplanes and
automobiles. Delco Electronics alone sells 7 million silicon
pressure sensors a year to its parent company, General Motors, for
use in power-train controls and diagnostics. But scientists at
Berkeley, Stanford, M.I.T., AT&T, IBM and a handful of other
research centers around the world see much broader possibilities
for minuscule machines. They envision armies of gnat-size robots
exploring space, performing surgery inside the human body or
possibly building skyscrapers one atom at a time. "Microelectronics
is on the verge of a second revolution," says Jeffrey Lang, a
professor of electromechanics at M.I.T. "We're still dreaming of
applications."

    A report to the U.S. National Science Foundation last year
listed dozens of near-term uses for the new micromachines. Among
them:

    Tiny scissors or miniature electric buzz saws to assist doctors
performing microsurgery.

    Micro-optical systems to focus lasers to the precision required
for fiber-optic communication.

    Miniature machine parts that could drive a new generation of
tiny tape recorders, camcorders and computers.

    Engineers and industrialists are rushing to put the new
technologies to use. M.I.T. has invested $20 million in a new
fabrication facility for micromachining and microelectronics.
Japan's Ministry of International Trade and Industry is considering
allocating nearly $70 million for the development of medical
microrobots. "I'm absolutely amazed at how fast this field has
progressed," says George Hazelrigg, a program director at the NSF,
the Government agency spearheading the U.S.'s micromechanics
effort.

    Human interest in tiny machines dates back to the clockwork
toys of the 16th century. But it was not until this century that
making things smaller became a matter of military and economic
survival. Spurred by the cold war and the space race, U.S.
scientists in the late 1950s began a drive to shrink the
electronics necessary to guide missiles, creating lightweight
devices for easy launch into space. It was the Japanese, though,
who saw the value of applying miniature technology to the consumer
market. In his book Made in Japan, Akio Morita tells how he proudly
showed Sony's $29.95 transistor radio to U.S. retailers in 1955 and
was repeatedly asked, as he made the rounds of New York City's
electronics outlets, "Who needs these tiny things?"

    American manufacturers eventually learned what the Japanese
already knew: that new markets can be created by making things
smaller and lighter. (The popular phrase in Japan is
kei-haku-tan-sho -- light, thin, short and small.) Ten years ago,
Black & Decker scored big when it shrank the household vacuum
cleaner from a bulky 11.2 kg (30 lbs.) to a 0.75-kg (2-lb.) device
dubbed the Dustbuster. Tandy and Apple Computers put the power of
a room-size computer into something resembling a
television-typewriter and created an industry worth $75 billion a
year.

    Now these breakthrough products look hopelessly oversize. Last
month Compaq unveiled a 2.2-kg (6-lb.) full-powered portable
computer that fits in a briefcase. Sharp and Poqet make even
smaller models that slip into a suit pocket. Today there are fax
machines, radar detectors, electronic dictionaries, cellular
telephones, color televisions, even videotape recorders that fit
comfortably in the palm of a hand.

    With the advent of silicon gears, springs and cantilevers,
machines will become smaller still. These miniature moving parts
can be etched on silicon using a variation on the photolithographic
technique used to make computer chips. To build a tiny rotating
arm, for example, layers of polysilicon and a type of glass that
can be removed with acid are deposited on a silicon base. A hole
for the hub is lined with the glass and then filled with
polysilicon. When the glass is etched away, the hub remains and the
arm is free to spin around its axis.

    Sensors like those made by Delco were the first to combine
microelectronics and micromachines on one chip. The typical
microsensor is a thin silicon diaphragm studded with resistors.
Because the electrical resistance of silicon crystals changes when
they are bent, the slightest stress on the diaphragm can be
registered by the resistors and amplified by electronic circuits.

    As prices drop, these devices will become ubiquitous. By 1995
the typical car may contain as many as 50 silicon sensors
programmed to control antilock brakes, monitor engine knock and
trigger the release of safety air bags. Similar sensors are already
employed in the space shuttle Discovery to measure cabin and
hydraulic pressures and gauge performance at more than 250 separate
points in the craft's main engines.

    Medical applications are also being rapidly developed.
Researchers at Maryland's Johns Hopkins have made a pill slightly
larger than a daily vitamin supplement that has a silicon
thermometer and the electronics necessary to broadcast instant
temperature readings to a recording device. By having a patient
swallow the pill, doctors can pinpoint worrisome hot spots anywhere
within the digestive tract. Future "smart pills" may transmit
information about heart rates, stomach acidity or neural functions.
Says Russell Eberhart, program manager at Johns Hopkins' Applied
Physics Laboratory: "This could change the way we diagnose and
monitor patients."

    Researchers at Tokyo University are pursuing an even more
ambitious goal. Working under Iwao Fujimasa, an artificial-heart
specialist, a team of 20 scientists is building a robot less than
1 mm (0.045 in.) in diameter that could travel through veins and
inside organs, locating and treating diseased tissue. The group
hopes to build a prototype within three years for testing on a
horse, but the researchers first must obtain gears, screws and
other parts 1,000 times smaller than the tiniest available today.

    The ultimate fantasy of the miniaturists is tiny robot
"assemblers" that could operate at the atomic level, building
finished goods one molecule at a time. This is the far-reaching
goal of an embryonic discipline called nanotechnology, so named
because it would require manipulating objects measured in
billionths of a meter (nanometers). In Engines of Creation, the
nanotechnologist's bible, K. Eric Drexler envisions a world in
which everything from locomotives to cheeseburgers is assembled
from molecular raw materials, much as proteins are created from
their amino-acid building blocks by the machinery of a living cell.

    Working with microscopic machines presents special challenges
to scientists. Not only do they risk inhaling their tools or
scattering them with a sneeze, but they also have to cope with a
new set of physical laws. The problem of friction, for instance,
looms ever larger as parts get smaller. The tiniest dust speck can
seem like a boulder. Rotating a hair-width dynamo through air
molecules, says AT&T's Gabriel, "is like trying to spin gears in
molasses."

    But the payoff can be enormous. As electronics manufacturers
have discovered, the laws of economics at the micro level are as
different as the laws of physics. A manufacturer might spend a
small fortune putting hundreds of moving parts and circuits onto
a single silicon chip. But when that chip goes into large-scale
production and millions of copies are made, the economies of scale
take over, and development costs virtually disappear.

    Unfortunately, there is a limit to how many transistors can be
squeezed onto the surface of a chip. Thus the attraction of
micromachines. They give engineers a way to shrink the moving parts
of a device rather than trying to shrink its computer controls
further. Some experts believe that within the next 25 years
micromachinery will do for machines what microelectronics did for
electronics. Given the progress over the past quarter-century, that
is saying a lot.


-- Scott Brown/San Francisco and Thomas McCarroll/New York