HOW TO MAKE A FUEL CELL? ……PRINT IT !

[Anonymous]

How do you make a fuel cell? Print it
The
technology that helped make black-light posters and concert T-shirts a
cultural mainstay is now being used to make fuel cells, chip packages
and PC components.South San Francisco, Calif.-based EoPlex Technologies
has come up with a technique for producing mechanical components with
industrial printers. Instead of embossing a logo through thin layers of
ink piled on top of each other, the company builds components by piling
thin, patterned layers of ceramics, metals and other materials on top
of each other and curing the individual layers as the structure takes
shape.These printed components, which consist of hundreds of layers,
can also contain fully integrated moving parts, hinges or sealed air
chambers.Although these parts can be cranked out now with conventional
manufacturing techniques, EoPlex claims that its technology will
greatly reduce the cost. Many parts can be produced simultaneously and
with less need of micromachining or assembly.Cost is a key
consideration if the futurists–who predict that sensors and computers
will become ubiquitous–are right. The technique is too beefy to
produce microprocessors inside sensors, but it can be used to make the
packages, power supplies and other necessary, albeit less
“intelligent,” components for pervasive computing.”A fuel cell reformer
can take two weeks on conventional manufacturing processes. It will
take us three minutes on a full-scale production line. We can now do a
prototype in a day,” said Arthur Chait, CEO of EoPlex. “We can
manufacture fully functional parts.”Several companies have examined
over the years the possibility of using printers to make parts.
Traditional manufacturing remains an expensive process involving
dedicated machinery and production lines. Printers are appealing
because they can be reprogrammed to print a variety of devices, thus
drastically cutting capital costs, real estate and even staff
sizes.Most have concentrated on inkjet printing. Hewlett-Packard, for
instance, has come up with a way to produce 3D design prototypes, which
can give engineers a better idea of what a finished product might
ultimately look like.British inkjet manufacturer Xaar, meanwhile, has
teamed up with researchers at the University of Manchester to develop
spray-on human bone cells. Xaar is also working with Sweden’s Thin Film
Electronics to create memory chips that can be sprayed (rather than
produced out of the highly expensive lithography and chemical etching
processes used by chipmakers today).Although EoPlex will likely one day
incorporate inkjet technology into its offerings, for now it
concentrates on techniques like screen printing where fluid is pressed
directly onto a surface by a drum or a plate. Conventional printing may
not draw as fine lines as inkjet printing, but it costs less.”If you’ve
ever seen posters printed, the process is similar,” Chait said. “They
print the yellow, then the red and then the blue.”Unlike posters, each
stage gets individually cured through heating. A single layer, for
instance, may contain ceramic material and a polymer. By heating this
layer after printing, the polymer will evaporate, leaving a void. In
the next printing layer, metals or a different type of ceramic will
then fill all or part of the void created in the previous round of
printing and burning.Right now, the company’s processes can produce
features measuring less than 50 microns. In the future, EoPlex will be
able to print features under 10 microns. (A micron is a millionth of
meter.)In semiconductors, 50 microns is gigantic–about the width of a
human hair–but for medical probe manufacturers or producers of small
solar cells, that’s small. Partly as a result of these relatively small
dimensions, features such as ball-and-socket joints or hinges can be
produced as an integrated element of a single component (rather than
represent the marriage of two separate miniature parts). The gap
between two moving parts actually represents layers of voids created
during the curing process.The curing also makes the latest layers bond
to the base of layers that went before it. After 300 rounds of
stenciling and heating layers, the finished product might emerge.The
company’s intellectual property largely revolves around coming up with
various printing fluids for different applications. Some metals have
relatively low evaporation points and therefore can’t be mixed with
other ones more tolerant of high temperatures. Some metals also conduct
electricity better than others; depending on the product being made,
that can be good or bad. Thus, Chait said, HP is less of a competitor
than a materials specialist like Japan’s Kyocera.”Typically there are
certain ceramics that go better with certain metals,” Chait said. “This
is more material science than printing. The trick is to get the
materials to work together.”A complete set of printers for producing
products with the company’s technology costs about $1 million, Chait
said, and can be squeezed into a space about the same size as a large
conference room. The start-up right now has the ability to make about
1,000 components a year, but it hopes to be capable of building 30
million units a year by 2011.EoPlex, which has received venture funding
from Draper Fisher Jurvetson and Labrador Ventures, will gain its
revenue from producing parts rather than licensing its intellectual
property. Right now, a number of manufacturers are looking at the
technology, Chait said. The first products made by EoPlex to hit the
market will probably be fuel cells, he predicted.”They are big, thick,
complex and involve multiple materials,” he said.

[Author]

June 2, 2006 at 11:45 AM