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Definition
Polymers are organic materials consisting of long chains of single molecules.
Polymers are highly adaptable materials, suitable for myriad applications. Until
the 1970s and the work of Nobel laureates Alan J. Heeger, Alan G. MacDiarmid and
Hideki Shirakawa, polymers were only considered to be insulators. Heeger et al
showed that polymers could be conductive. Electrons were removed, or introduced,
into a polymer consisting of alternately single and double bonds between the carbon
atoms. As these holes or extra electrons are able to move along the molecule,
the structure becomes electrically conductive. Thin
Film Electronics has developed a specific group of polymers that are bistable
and thus can be used as the active material in a non-volatile memory. In other
words, the Thin Film polymers can be switched from one state to the other and
maintain that state even when the electrical field is turned off. This polymer
is "smart", to the extent that functionality is built into the material
itself, like switchability, addressability and charge store. This
is different from silicon and other electronic materials, where such functions
typically are only achieved by complex circuitry. "Smart" materials
can be produced from scratch, molecule by molecule, allowing them to be built
according to design. This opens up tremendous opportunities in the electronics
world, where "tailor-made" memory materials represent unknown territory Polymers
are essentially electronic materials that can be processed as liquids. With Thin
Film's memory technology, polymer solutions can be deposited on flexible substrates
with industry standard processes like spin coating in ultra thin layers. Digital
memory is an essential component of many electronic devices, and memory that takes
up little space and electricity is in high demand as electronic devices continue
to shrink Researchers from the Indian Association for the Cultivation of Science
and the Italian National used positive and negative electric charges, or space
charges, contained within plastic to store binary numbers Research Council. A
polymer retains space charges near a metal interface when there is a bias, or
electrical current, running across the surface.
These charges come either from electrons, which are negatively charged, or the
positively-charged holes vacated by electrons. We can store space charges in a
polymer layer, and conveniently check the presence of the space charges to know
the state of the polymer layer. Space charges are essentially differences in electrical
charge in a given region. They can be read using an electrical pulse because they
change the way the devices conduct electricity.
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