The document discusses plastic electronics and how plastics can be made conductive. It begins by explaining how plastics were traditionally considered insulators but can become conductive through doping, which involves removing or adding electrons. This allows for conjugated double bonds that allow electron mobility. Common conductive plastics include polyacetylene and pentacene. Applications discussed include plastic LEDs, transistors, solar cells, and lasers. Plastic electronics offer advantages over silicon like lower costs, flexibility, and being easier to manufacture at ordinary temperatures and pressures. The summary highlights key applications and how doping makes plastics conductive.

1. PLASTIC
ELECTRONICS
V.FOUTHIKA ( 17304009)
M.TECH(ECE)

2. Introduction
 Plastic is considered as an insulator, a material that
doesn't conduct electricity very well.
 In fact prior to the 1970s, all synthetic polymers were
considered as electrical insulators.
 In 1978, a landmark paper described treating
polyacetylene with halogens, and in doing so
increased its electrical conductivity to almost the
level of a poor metal.

3. Introduction
 The men principally credited for the discovery and
development of highly conductive polymers (at least
of the rigid backbone “polyacetelene”) class are Alan
J.Heeger, Alan G.Macdiramid and Hideki Shirakawa,
who were jointly awarded the nobel prize in
chemistry in 2000 for development of oxidized,
iodine-doped polyactelene.
 This opens the gateway of plastic electronics.

4. Disadvantages of Conventional
Semiconductors
 Manufacturing silicon requires
 High temperatures (400-1400°C).
 High vacuum environments.
 Very clean environments.
 This increases the cost of production.
 Conventional electronic devices are rigid

5. Advantages of Plastic Electronics
 Can be manufactured easily under ordinary
conditions.
 More compatible with manufacturing
processes that use other plastics.
 Renowned for their excellent mechanical
properties, such as strength and flexibility.
 Cheap and light, useful features for biomedical
and other portable applications.

6. Feature of plastics
 Strength
 Flexibility
 Light weight
 Malleability.
 Low cost

7.  Strength.
Plastic can be hard enough to be used as a canopy for a
fighter jet. You can trust it to replace a heart valve. And
if that material is “smart” (for example, if it contains an
embedded microchip to store data or has other special
computer-enabled features), it can warn you when the
heart is working too hard.

8.  Flexibility.
Plastic can be made as flexible as you want it to be. It
can be stretched, bounced and twisted. It can snap back
or hold its new shape.

9.  Light weight.
Plastic weighs less than glass and metals, which is why
it’s a natural replacement for materials in today’s
displays and batteries.

10.  Malleability.
How would you like it? As a box, a rod, a ball? As a
fiber, a fabric, a tape? As a button, a lens, a trampoline?
Just look around at all the shapes plastic takes in our
lives and imagine making those materials smart.

11.  Low cost.
Plastic is so cheap that we routinely throw it away.Though
there are specialty plastics, these materials are generally
not rare or precious. When a new application comes up,
they can be made in bulk.

12. The Chemistry behind …
 Conventional plastic is a lousy conductor
 Loose molecular bonds, which make the material so
flexible, make it more difficult for the electrons to
travel through it.
 But arranging polymer molecules into long, straight
rods lets electrons flow freely, approximating the
conductivity of traditional materials like silicon or
copper.

13. Molecular Model of a Polymer

14. How can plastic becomes
conductive?
 Plastics are polymers, molecules that form long
chains, repeating themselves like pearls in a necklace.
In becoming electrically conductive, a polymer has to
imitate a metal, ie, its electrons need to be free to
move and not bound the atoms
 The first condition for this is that the polymer consist
of alternating single and double bonds called
conjugated double bonds.

15. Mobility Features
 mobility of a typical conducting plastic used to be
around 0.1 cm2 / volts
 Recently, a new class of polymers (pentacene) has
been found in which the mobility has been pushed up
to 3 cm2/volts.
 Scientists working on pentacene estimate a number
close to 50 cm2/volts as the limit of achievable
mobility for this special polymer `

16. Contd…
 Polyacetelene, prepared through polymerization of the
hydrocarbon acetylene has such a structure:

17. Contd…
 However, it is not enough to have conjugated double
bonds.
 To become an electrically conductive, the plastic has
to be disturbed – either by removing electrons from
(oxidation),or inserting them into (reduction), the
material.
 This process is known as doping.

18. Constructional Details
 Dielectric layers are made from conventional,
electrically insulating polymers.
 Conjugated polymers are used for the semi-
conducting components.
 Electrodes & interconnects are fabricated from
highly doped conducting polymers.

19. Manufacturing
 The heart of modern electronics are microchips
circuits and wiring diagrams are designed and micro
miniaturized to the point that thousands or even
millions of circuits are contained in a one inch square
chip which is burned on to ultra thin inorganic
materials life refined silicon using very high
temperature.
 Plastic electronics on the otherhand, follow a
different manufacturing process.

20. Contd…
 The process starts with the manufacturing of
large sheets of PET plastics. The flexible but
tough material used in the production of
plastics bottels.
 Circuits are then printed on these sheets using ink-jet
printers or using techniques used to print magazines
and newspapers resulting in a process that is cheap,
easy to do and faster to produce.

21. Contd…
 The plastic circuit will be used as the active matrix
back panes for large but flexible electronic displays.
In an active matrix display, every dot on displays
managed by a switching element such as thin flim
transistors(TFTs).

22. Applications of Plastic Electronics
 PolyLED
 Plastic Transistors
 Plastic Solar Cells
 Plastic LASERs

23. Polymer Light-Emitting Diode
PolyLED
 Light is transmitted in all directions with the same
intensity
 Consume much less power than today's devices.
 High contrast and brightness to make a high-quality
display that can be read easily in both bright and dark
environments
 Don't break when dropped

24. Structure & Working of PolyLED

25. Plastic Transistors

26. Thin Film Transistor

27. Working of TFT

28. Plastic Solar Cells
 At the heart of all photovoltaic devices are two
separate layers of materials,
 one with an abundance of electrons ;"negative pole,"
:- poly(3-hexylthiophene), or P3HT
 one with an abundance of electron holes "positive
pole.“:- Cadmium Selenide (CdSe)

30. Plastic LASERs
 The Future of Lasers is Plastic
 Lightweight "plastic lasers" would be cheaper, easier
and safer to make than semiconductor lasers.
 produce all the colors rainbow
 shaped easily into films, rings, microscopic discs or
any desired shape for various uses,
 plastics act as their own cavities, not only emitting
laser light but containing and focusing it.

32. Conclusion
 In conclusion, while many obstacles still remain in
the development of plastic electronic devices, the
applications of these devices are not just science-
fiction.
 There is little doubt that, 'plastic electronics' will
become part of our lives within the next decade.
 Chemists will be vital members of the
interdisciplinary teams that do this work.
 Within the next decade, we will see plastic electronic
devices giving intelligence to objects around us and
significantly changing our lifestyle, just like the
invention of plastics did in the twentieth century

33. References
 [1].“plastic electronics based on semiconducting polymers”-
m.schroder, s.sensfuss, a.bernds published by IEEE 06 august
2002.
 [2].”polymer electrionic system”-k.bock published by IEEE on
18 july 2005
 [3]. http://www.discoverengineering.org
 [4]. http://www.plasticelectronics.org
 [5]. http://www.plastic-electronics2010.com

34. Thank you