X-Message-Number: 8119
Date: Mon, 21 Apr 1997 15:05:16 -0400 (EDT)
From: The Hitman <>
Subject: CRYONICS NASA Explains How Molecular-Sized Gears Might Work (fwd)

Thought you all might find this interesting, hopefully
no one has already posted about this as I am a bit behind 
in my reading.

RELEASE:  97-75

NASA EXPLAINS HOW MOLECULAR-SIZED GEARS MIGHT WORK

     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:  

               http://www.nas.nasa.gov/nanotechnology.  

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

http://ccf.arc.nasa.gov/dx/basket/storiesetc/Nanopix.html

     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. 

                           -end-

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.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=8119