Nanotechnology and smart materials
By Bill Spence
Publisher, NanoTechnology Magazine
N anotechnology, the idea of building things deliberately with
individual atoms, is the shotgun marriage of chemistry and
engineering. If we can place atoms on a structure under construction
individually, this opens up a realm of super-large molecules not
found in nature, but designed by engineers (adhering to the laws of
chemistry). Structures--big structu res or microscopic
structures--and machines could be made of materials with unusual
physical properties, like carbon in its ultra-strong form: diamond.
The concept of self-replicating machinery would be possible.
Working on the atomic scale, mechanical computers with the power of a
mainframe could be built so small that several hundred would fit
inside the space of a biological cell.
If you combined microscopic motors, gears, levers, bearing, plates,
sensors, power and communication cables, etc., with powerful
microscopic computers, you have the makings of a new class of
materials: "smart materials."
Programmable smart materials could shape-shift into just about any
desired object. A house made of smart materials would be quite useful
and interesting. Imagine a wall changing color at your command, or
making a window where their was none before. How about designing new
drapes of any style found in the smart-materials software or from s
ome source on the Internet. This is all purely mechanical and can be
done today, although with much larger parts, resulting in a coarser
effect (and at great expense!).
A fabulous type of smart material was invented by Rutgers
University's Dr. J. Storrs Hall, computer scientist, moderator of the
sci.nanotech newsgroup and creative nanothinker. He calls his
brainchild, "Utility Fog."
This "intelligent" polymorphic (shape-changing) substance consists of
a mass of tiny, identical nanoengineered robots. Each utility
"foglet" robot is mostly telescoping arms 5 to 10 millionths of a
meter long with a central globular body 1 or 2 millionths of a meter
wide, housing motors, a battery and one of those powerful
nanocomputers. Dr. Hall designed the 'bot with 12 arms that can be
waved back and forth and can grip the ends of other robot arms,
making power and communication connections; 12 arms, so some could be
free briefly when changing nei ghbors and still be connected to the
mass. Also, such an octet-truss structure (invented by Buckminster
Fuller) remains rigid even if all the arms are connected to the
bodies by simple hinges. This avoids a more complicated attachment
Each robot body is small in relation to its arm spread, and the arms
are relatively thin. This results in the foglet taking up only 2% or
3% of the space in any volume they fill;, the balance is left for air
and passing light. A room filled with Utility Fog would be fairly
transparent, though larger volumes would become cloudy at a distance.
Much larger foglets can be built with today's technology, but the
expense of producing enough of them to do anything useful would be
most prohibitive. Filling an average house with the microscopic
variety would require trillions of foglets, so the whole concept
depends on the economics of automatic nano-assembly to be remotely
Now for the fun part. With all this computing power, these foglets
can be p rogrammed with a spectrum of behaviors that mimic materials
of different mass, motion, appearance and function. Each foglet can
sense force along each and every arm, and can react according to the
magnitude and relation of that force.
In the words of Dr. Hall in a recent article in NanoTechnology
Magazine: "If the program says, extend when the force is trying to
stretch, retract when it is trying to compress, you have a soft
material. If it says, resist any change up to a certain force, then
let go, you have a hard but brittle material. If the programming
says, maintain a constant total among the extension of all arms, but
otherwise do whatever the forces would indicate, and when a
particular arm gets to the end of its envelope, let go, and look for
another arm coming into reach to grab, you have a liquid. If you
allow the sum of the arm extensions to vary with the sum of the
forces on the arms, you have something that approximates a gas within
a certain pressure range. Note that because the fogl ets can use
their own power to move or resist moving, the apparent density and
viscosity of the fluid can be anything from molasses to near vacuum.
"Run a distributed program that, at a specified time, changes a
certain volume from running water to running wood. A solid object
would seem to appear in the midst of fluid. It can just as easily
disappear. Now fill your entire house with the stuff, running air in
background mode. Have an operating system that has a library of
programs for simulating any object you may care to; by giving the
proper command you can cause any object to appear anywhere at any
time. You could carry a remote control. . . .More ambitiously, since
you're embedded in the fog, it can sense every detail of your bodily
position. It forms a 'whole-body dataglove,' and you can control it
with extremely subtle gestures.
"At the ultimate extreme, the foglets can carry various special
sensors ranging from simple electrodes with voltmeters to SQIDs to
form an extremely high bandwidth p olygraph. With proper programming
the fog would almost be able to read your mind.
This combination of extreme reactivity to control and virtually
limitless creative and operational ability suggest a comparison with
the Krell machine in 'Forbidden Planet.'
Hall offers the average person with a bucket of Utility Fog a great
stage career in Las Vegas with these observations: "Here's a short
list of the powers you'd have or appear to have if embedded in fog:
Creation--causing objects to appear and disappear on command.
Levitation--causing objects to hover and fly around.
Manipulation--causing forces (squeezing, hitting, pulling) on objects
(real ones) at a distance. Teleportation--nearly any combination of
telepresence and virtual reality between fog-filled locations."
For a more detailed account of Utility Fog, pick up a copy of a book,
edited by B.C. Crandall, titled, "Nanotechnology: Molecular Specul
ations on Global Abundance," and read Dr. Hall's chapter, "The Stuff
that Dreams are Made Of." Hall writes of a future Utility Fog-filled
zoo, in which no cages exist between you and the animals. The animals
roam and mingle with the zoological patrons, each kept safe from each
other by an invisible hand. You will also find concepts in this book
by other nanotechnologists that are sure to please.
The future will never move the same.
(c) 1997 NanoTechnology Magazine