~e; Electrotextiles

[bc <human@electronetwork.org>]

// this is a great article on the advancement of electrical
// textiles, and of note is the dual-use aspect, that these
// technologies are literally 'battle proven" in military R&D
// gear, such as embedded radio transmitter antennas,
// prior to becoming .mp3 viable consumer wear. i also
// wonder what those who weave with traditional fabrics
// might do with such a material possibility, if a wall hanging
// might be made out of illuminated fiberoptic glass strands,
// some day, or, a matrix/grid/meshwork of electrotextiles in
// which various functions may be performed for a dwelling,
// with light, heat, cooling, acting as a sensor, as a receiver
// for signals, a broadcast transmitter, who knows what...


For the Smart Dresser, Electric Threads That Cosset You

February 6, 2003
By ANNE EISENBERG

DESIGNERS traditionally choose textiles based on their
beauty, strength or cost. Now they can choose them based on
their ability to conduct electricity.

These days some, including the chemical giant DuPont, are
producing yarns that can transmit electrical signals or
current. The yarns, made of synthetic or metallic fibers,
are woven or knitted into cotton or polyester to produce a
new type of cloth known as electrotextiles.

The conductive fibers of electrotextiles can be connected
to chips and batteries to create circuits that may one day
have many applications. Used in car upholstery, for
instance, electrotextiles and their circuits could sense a
passenger's weight and tell an air bag to adjust its force
accordingly. Fleecy versions of the electronic cloth could
keep anyone snuggled under them toasty at a football game.

Electrotextiles may soon be a reality not only in blankets
and car seats, but in shirts, trousers and jackets, too.
Call one shade of such garments "electric blue," and you
may be describing its function as well as its color.

"The clothing we wear now doesn't contain electronic
elements," said Dr. Michael S. Shur, a physicist at
Rensselaer Polytechnic Institute who recently helped
organize a symposium on electronics in unconventional
materials, including textiles. "But every type of clothing
will have electronic functions in 10 years," he predicted,
from materials that incorporate global positioning systems
and blood pressure sensors to fabrics that can change their
color and pattern.

So far, the technology of electrotextiles is found mainly
in military applications, Dr. Shur said, citing as an
example antennas woven into soldiers' vests. But commercial
products are starting to appear. "People are developing
radios only two or three millimeters big that can be
incorporated into washable electrotextiles," he said. The
devices would be robust enough to make it through the
washer. "The radios are just like buttons - you don't need
to remove buttons when you wash a dress," he said.

The soft, flexible fibers woven into the electrotextiles
aren't meant to light up floor lamps, but they are
conductive enough to transmit signals, said John D. Ross,
business manager for Aracon, the trade name of a conductive
fiber made by DuPont's Advanced Fibers Systems division in
Richmond, Va.

Aracon is a metal-clad form of Kevlar, the ultrastrong
DuPont polymer known for its use in bullet-resistant vests.
"The metal cladding makes Aracon conductive, like a copper
wire is conductive," Mr. Ross explained.

Sometimes the cladding is silver, chosen for its
solderability, or nickel, which generally resists
corrosion. After the yarn bundle is clad with metal, it is
insulated with a polymer. "You don't want it close to your
skin if it's not insulated," Mr. Ross said, "even with low
voltage."

Aracon is one of the conducting fibers used in an
electronic T-shirt that keeps track of its wearer's vital
signs, said Dr. Sundaresen Jayaraman, a professor of
textile engineering at the Georgia Institute of Technology
and chief operating officer of Sensatex, a New York City
company that markets the shirt.

Dr. Jayaraman developed the technology for the body-sensing
fabric with financing from the federal government's Defense
Advanced Research Projects Agency. He is now adapting the
shirt for use by firefighters.

The stretch cotton T-shirt, presently in prototype, keeps
track of heart rate, body temperature and other vital
signs, transmitting them wirelessly to a PC from a
pager-like device that snaps into the shirt, he said.

The conductive fibers of electrotextiles may be interwoven
with the material of a garment, or added to it in narrow
strips of ribbon or webbing that are sewn, for instance,
around the neck or waist. At Malden Mills Industries in
Lawrence, Mass., stainless steel conductive fiber is
knitted directly into the company's Polartec cloth to
create a lightweight electric blanket, said David L.
Costello, business manager.

The stainless steel is given a proprietary coating so that
it can run on the company's production machinery, he said.

Infineon Technologies, the German semiconductor
manufacturer, uses strips of conductive textile to connect
the electronic elements of an MP3 player built into a
fashionable charcoal-gray jacket and hood. A prototype of
the musical jacket was shown last October at a symposium on
wearable computers in Seattle.

Dr. Stefan Jung, a senior scientist at Infineon's Emerging
Technologies Laboratory in Munich, said that the connective
fibers in the jacket are lightweight bundles of hair-thin
copper wires coated with silver and polyester and connected
to a tiny microcontroller sealed in plastic.

"The conductive fibers lead to a pocket," Dr. Jung said.
"Then you can reach in and disconnect the battery pack and
MP3 storage card when you need to." Electronic fabric that
also functions as a drawstring on the jacket hood leads to
the headphones. Touch controls for the player are woven
into a strip that is stitched to the sleeve of the jacket.

Dr. Patricia Wilson, a materials scientist at
Foster-Miller Inc., a research and development concern in
Waltham, Mass., has spent the last few years in part
working on the developing technology of electrotextiles.

One of the company's projects has been creating antennas
that can be incorporated into military clothing. In one
version of an antenna, a webbing of conductive textile is
sewn onto a vest to create the radiating part of the
antenna. The webbing is then connected to the radio.

"The radio guy wearing a one-meter-long whip antenna is an
obvious target in combat," she said. "This way, he can
remain in contact without attracting attention." Military
applications of electrotextiles are being evaluated at the
Natick Soldier Center, an Army research and development
center in Natick, Mass.

Whether they are intended for soldiers or civilians,
electrotextiles in their current incarnations require an
external power source, normally a battery. But Dr. Shur of
Rensselaer said he could envisage a time when the power
supply could be part of the fabric as well - solar cells
woven into the back of a jacket, perhaps, to power the
electronics within.

"It's a good application of solar cells," Dr. Shur said.
"After all, people wear their clothes all day."

http://www.nytimes.com/2003/02/06/technology/circuits/ 
06next.html?ex=1045571219&ei=1&en=f1218021100c8df2

Copyright 2002 The New York Times Company

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