Ill. --- The potential applications for flexible plastic
electronics are enormous -- from electronic books
to radio frequency identification (RFID) tags to electronics
for cell phones, personal digital assistants (PDAs)
and laptop computers -- but certain technological
hurdles must be overcome before we see such widespread
a Northwestern University team of materials chemists
report a breakthrough in the race to find the right
materials for producing cost-effective, high-performance
plastic electronics. The findings appear in the Proceedings
of the National Academy of Sciences (PNAS).
The team, led by Tobin J. Marks,
Vladimir N. Ipatieff Professor of Chemistry and professor
of materials science and engineering, has designed
organic molecules that self assemble into an ultra-thin
layer (less than six nanometers thick) for use in
the dielectric, or nonconducting, component of a transistor.
Their tailored molecular components reduce both operating
voltage and power consumption in organic thin-film
transistor (OTFT) structures, making low-power consumption
OTFTs a reality.
"This means having plastic
electronics the size of a pen battery -- rather than
an automobile battery -- power your cell phone,"
said Marks. "And, instead of being carved out
of silicon, transistor structures would be printed
in a fashion similar to that of newspapers, but with
organic molecules as the ink and plastic as the paper.
Much as the New York Times prints a different edition
of the newspaper every day, we could flexibly print
a wide variety of electronic devices quickly, easily
Examples include RFID tags
for labeling items in a store or tracking them in
a factory. "You could walk up to a cash register
at the grocery store," said Marks, "and
it would automatically sense what each item costs
and whether or not it has passed its expiration date
-- all in one step."
In their paper, Marks and fellow
authors Antonio Facchetti, research professor of chemistry,
and Myung-Han Yoon, a graduate student in chemistry,
showed that their new nanodielectric multilayers have
very high capacitances (the ability to store an electrical
charge) and excellent insulating properties and are
compatible with a variety of organic semiconductors
and substrate materials, the other key components
of a transistor.
Contact: Megan Fellman