Scientists at the Air
Force Research Laboratory Materials and Manufacturing Directorate (AFRL/RX),
in a concerted effort with Plextronics, Inc., and the Pennsylvania NanoMaterials
Commercialization Center, both located in Pittsburgh, Pa., developed a ready-to-use,
cost-reducing technology that can capture sunlight and store it as energy to
power Global Positioning System components, portable communications, and other
devices for U.S. soldiers.

Plexcore® technology, depicted here, allows solar cells to form-fit soldiers’ uniforms to power GPS components and communication devices, and could also be used to “print” solar panels onto thin films incorporated into military tents. Commercial applications include solar energy batteries for cell phones, radios, and other portable devices. (U.S. Air Force photo)
According to 2nd Lt. Christopher A. Vaiana of the Directorate's Nonmetallic
Materials Division, AFRL/RX provided guidance and funding to develop a special
"conductive ink" that can be used to make printed organic photovoltaic
solar cell panels on very thin, flexible surfaces using ink-jet printing. This
new technology, called Plexcore®, developed and manufactured by Plextronics,
allows solar cells to form-fit soldiers' uniforms. It can also be used to print
solar panels onto thin films in military tents, Lieutenant Vaiana said.
The agreement between AFRL/RX and the Commercialization Center includes the
development of a technology roadmap identifying technologies AFRL/RX needs and
is interested in funding. The Center is responsible for reporting these needs
to industry and requesting proposals. Next, a team of personnel representing
both organizations carefully examines the proposals and indentifies those with
the most promise to receive funding, Lieutenant Vaiana explained.
The agreement has already resulted in the successful program with Plextronics,
whose primary focus is organic solar cell and organic light emitting diodes,
and more specifically, the conductive inks and process technologies that enable
such applications, he pointed out.
"Solar power and solid-state lighting offer substantial promise as approaches
toward the development of practical alternative energy technology," Lieutenant
Vaiana stated. "Combined with the low-cost manufacturing methods of printed
electronics, solar and solid-state lighting panels could become economical and
environmentally compatible solutions to current day and future energy challenges.
"Military and commercial operations demand portable, highly efficient
power sources. Using the power provided by natural sunlight via solar cells
is an attractive option, yet has thus far been restricted by cost and size,"
Lieutenant Vaiana continued.
"Plextronics' new technology represents a significant step forward in
printing inexpensive solar cells capable of powering a wide range of portable
devices such as cell phones and radios. Key outcomes include lower costs and
reduced logistical footprints for military operations across the battlefield
environment," he added.
Plexcore® has some important advantages over today's silicon-based solar
cell panels, including highly substantial cost reduction: approximately $50
per square meter versus $500 per square meter for silicon-based panels, Lieutenant
Vaiana explained.
"The technology has won best-in-class recognition for unmatched solar
power efficiency. The research and development effort has also helped streamline
the manufacturing process for printed OPV devices, resulting in reduced costs
and trimmed production times. Compared to other organic photovoltaic materials,
Plexcore® offers world-class efficiency," he said.