INK-JET PRINTABLE CONDUCTING POLYANILINE BASED INK: A PROMISING
CANDIDATE FOR LOW COST, FLEXIBLE ELECTRONICS DEVICES
Milind V. Kulkarni*, Bharat B. Kale, Sanjay K. Apte and S. D. Naik
Nanocomposite Laboratory,
Centre for Materials for Electronics Technology (C-MET),
Department of Information Technology, Govt. of India
Panchawati, Off Pashan Road,
Pune 411 008, INDIA
Corresponding Author E-mail address: milindcmet@yahoo.com /milind@cmet.gov.in
Flexible electronics is the future
trend of the worldwide electronic industry.
Organic materials have attracted a lot of
attention
for
building
large-area,
mechanically flexible electronic devices1.
Organic light emitting diodes for flat panel
displays are ready for mass production2 and
significant progress has also been made in
organic thin film transistors and organic
solar cells3.
There is a strong desire to
develop new advanced materials that can
overcome the potentially limiting scaling
difficulties present in the semiconductor
industry. Development of future information
technology could come from data storage
incorporating these advanced materials.
Organic materials or polymers are promising
candidates for electronic devices in new
information technologies4. The use of these
materials
provides
a
simplified
manufacturing process yielding low cost,
flexible and light weight devices that have
active device area approaching the
nanoscale. Besides the obvious application
of flexible electronics in flat panel displays.
Flexible circuits are also promising for use
in applications such as radio frequency
identification (RFID) tags, low cost sensors,
and other disposable electronic devices. In
particular, devices based on organic
semiconductors are considered to be very
promising for these applications since they
may potentially be fabricated entirely using
printing technologies, eliminating the need
for such major cost points lithography,
vacuum processing including physical vapor
deposition, plasma etching, and chemical
vapor
deposition
(CVD),
while
simultaneously allowing the use of reel-toreel processing, resulting in reduced
substrate handling and clean-room costs as
well. Furthermore, since printing is
inherently additive in nature, material and
disposal costs are also expected to be
reduced, resulting in an extremely low net
system cost. In the last few decades,
Synthetic Metals or Inherently
Conducting Polymers (ICPs) have been very
actively pursued. Several discoveries
brought the ICPs to full commercialization
with applications in displays, sensors,
polymer
light-emitting
diodes,
and
photovoltaic and electrochromic devices5.
Since the discovery of conducting polymers,
they have become extremely attractive
materials, due to their tunable band gaps and
redox properties, processability, lightness,
resistance against corrosion and low cost.
Also, compare to silicon technology,
polymers not only flexible, but costs less to
the
manufacturers.
Among
organic
conducting polymers, polyaniline (Pani) is
regarded as one of the most technologically
promising electrically conductive polymers
due to its ease of synthesis, low cost,
versatile processability and relatively stable
electrical conductivity 6.
Inkjet printing is now an important
technology for depositing layers of
conductive polymers7. The method works by
ejecting an ink through very fine nozzles,
10-200 μm diameter. The jetted stream is
broken into a series of droplets that can be
deposited on flexible and non flexible
substrates. The advantages of inkjet printing
over other thin film techniques lie in its
patterning capability, the efficient use of
material, the high speed and low cost of the
process, and in the fact that thin films can be
printed on flexible substrates. To print
electronics, conducting ink is a key factor
for the proper performance of printed
electronics. In this report, we would like to
present the synthesis of Ink-Jet Printable
Conducting Polyaniline based ink and its
Physico-chemical
characterization
and
successive printing of IDT pattern on
flexible untreated polymeric substrates. This
conducting polymer based aqueous ink will
have potential applications in low cost
Sensors, Solar cells, Electrochromic Devices
and in Printed, Flexible Electronics Devices.
References:
1.
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C. J. Brabec, N. S. Sariciftici, J. C.
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J. C. Scott, Science (2004), 304, 62.
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M. F. Mabrook, C. Pearson and M.
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(a)
(b)
(c)
Fig.1 (a) Polyaniline based aqueous ink
and (b, c) Ink-Jet printed IDT patter on
untreated flexible polymer substrate
Corresponding Author
E-mail address: milindcmet@yahoo.com
/milind@cmet.gov.in