NANO: NASA Explains How Molecular-Sized Gears Might Work

Patrick Wilken (
Fri, 2 May 1997 12:42:44 +1000

Sent from: abrupt <>

Don Nolan-Proxmire
Headquarters, Washington, DC April 21, 1997
(Phone: 202/358-1983)

John Bluck
Ames Research Center, Mountain View, CA
(Phone: 415/604-5026)

RELEASE: 97-75


A technical paper sponsored by NASA and recently accepted by
the journal "Nanotechnology" explains how molecular-sized gears
might work.

"Thanks to simulation of molecular-sized gears by a NASA
supercomputer, hope is growing that products made of thousands of
tiny machines that could self-repair or adapt to the environment
can ultimately be constructed," said Al Globus, a co-author of the paper.

Authors are Jie Han, Al Globus, Richard Jaffe and Glenn
Deardorff of NASA's Ames Research Center, Mountain View, CA.

Researchers have simulated attaching benzyne molecules to the
outside of a nanotube to form gear teeth, explained Globus.
Nanotubes are molecular-sized pipes made of carbon atoms. "You
also need a cooling system for gears. We used a supercomputer to
simulate successful cooling of molecular-sized gears with helium
and neon gases," he explained.

To "drive" the gears, the computer simulated a laser that
served as a motor. "The laser creates an electric field around
the nanotube. We put a positively charged atom on one side of the
nanotube, and a negatively charged atom on the other side. The
electric field drags the nanotube around like a shaft turning," he said.

"These gears would rotate best at about 100 billion turns per
second or six trillion rotations per minute (rpm)," he added. The
gears that Globus and others have simulated with computers would
be about a nanometer across. A nanometer is one-billionth of a meter.

One practical use of nanotechnology would be to build a
"matter compiler," said Creon Levit, a Globus colleague at Ames.
"We would give this machine, made of nano parts, some raw
materials, like natural gas, for example. A computer program
would specify an arrangement of atoms, and the matter compiler
would arrange the atoms from the raw materials to make a macro-
scale machine or parts," Levit added.

"A matter compiler is not just science fiction. In the
biotechnology industry, there are already 'peptide synthesizers'
in use. You give them a sequence of amino acids you want
produced, and the machine will create those peptides. But you
can't make rockets out of peptides," he said. A peptide is a
sequence of amino acids.

"A step along the way to make an aerospace matter compiler is
an even smaller hypothetical machine, the 'assembler/replicator,'"
said Globus. "The replicator can make a copy of itself, just as a
living cell can duplicate itself.

"We would like to write computer programs that would enable
assembler/replicators to make aerospace materials, parts and
machines in atomic detail," he said. "Such materials should have
tremendous strength and thermal properties." Further information
on these materials can be obtained on the researchers' Internet
page at URL:

An image of the nanogear from a computer simulation is
available at the following URL:

A long range goal, according to Globus, is to make materials
that have radically superior strength-to-weight ratio. Diamond,
for example, has 69 times the strength-to-weight ratio of
titanium. A second goal is to make "active" or "smart" materials.

"There is absolutely no question that active materials can be
made," Globus explained. "Look at your skin. It repairs itself.
It sweats to cool itself. It stretches as it grows. It's an
active material," he said.

Globus strongly emphasized that making real nanomachines may
be decades away, but he said that computer simulations suggest the
tiny machines are possible after engineers learn to build
nanoparts and to assemble nanomachines.

The nanogear and other related Ames research is a
collaboration between the Ames Numerical Aerospace Simulation
Systems Division and the Ames Computational Chemistry Branch.


Note to Editors: A black & white image of the molecular-sized
gears is available by calling the Broadcast & Imaging Branch at
202/358-1900. The photo number is 97-H-220.