60545320 plastic memory report

7/29/2019 60545320 Plastic Memory Report

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1. INTRODUCTIONImagine a scenario where the memory stored in your digital camera or personal

digital assistant is partially based one of the most flexible materials made by man-

plastic.

The recent development in the memory was a new form of permanent computer

memory which uses plastic and may be much cheaper and faster than the existing

silicon circuits which was invented by Researchers at Princeton University working

with Hewlett-Packard. This memory is technically a hybrid which contains a plastic

film, a flexible foil substrate and some silicon, that could store more data and cost less

than traditional silicon-based chips for mobile devices such as handheld computers,

cell phones and MP3 players.

A conducting plastic has been used to create a new memory technology with the

potential to store a megabit of data in a millimeter square device - 10 times denser than

current magnetic memories. The device should also be cheap and fast, but cannot be

rewritten, so would only be suitable for permanent storage.

The device sandwiches a blob of a conducting polymer called PEDOT

(POLYETHYLENE DIOXYTHIOPENE) and a silicon diode between two perpendicular

wires. Substantial research effort has focused on polymer-based transistors, which could form

cheap, flexible circuits, but polymer-based memory has received relatively little attention.

However, turning the polymer into an insulator involves a permanent chemical change,

meaning the memory can only be written to once. Its creators say this makes it ideal for

archiving images and other data directly from a digital camera, cell phone or PDA, like an

electronic version of film negatives.

While microchip makers continue to wring more and more from silicon, the most

dramatic improvements in the electronics industry could come from an entirely different

material plastic. Labs around the world are working on integrated circuits, displays for


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handheld devices and even solar cells that rely on electrically conducting polymersnot

siliconfor cheap and flexible electronic components. Now two of the worlds leading chip

makers are racing to develop new stock for this plastic microelectronic arsenal: plastic

memory. Advanced Micro Devices of Sunnyvale, CA, is working with Couture, a startup inWoburn, MA, to develop chips that store data in polymers rather than silicon. The

technology, according to Coatue CEO Andrew Perlman, could lead to a cheaper and denser

alternative to flash memory chipsthe type of memory used in digital cameras and MP3

players. Meanwhile, Intel is collaborating with Thin Film Technologies in Linkoping,

Sweden, on a similar high capacity plastic memory.


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2.PRESENT MEMORY TECHNOLOGY SCENARIOIn order to enable computers to work faster, there are several types of memory available

today. Within a single computer there are more than one type of memory.

Memory

DRAM SRAM NVRAM FLASH EEPROM PROM EPROM

RAM: The RAM family includes two important memory devices: static RAM (SRAM)

and dynamic RAM (DRAM). The primary difference between them is the lifetime of the

data they store. SRAM retains its contents as long as electrical power is applied to the

chip. If the power is turned off or lost temporarily, its contents will be lost forever.

DRAM, on the other hand, has an extremely short data lifetime-typically about four

milliseconds. This is true even when power is applied constantly.

ROM: Memories in the ROM family are distinguished by the methods used to write new

data to them (usually called programming), and the number of times they can be

rewritten. This classification reflects the evolution of ROM devices from hardwired to

programmable to erasable-and-programmable. A common feature of all these devices is

their ability to retain data and programs forever, even during a power failure.

PROM: PROM (programmable ROM), is purchased in an unprogrammed state, then the

device programmer writes data to the device one word at a time by applying an electrical

charge to the input pins of the chip. Once a PROM has been programmed in this way, its

contents can never be changed. If the code or data stored in the PROM must be changed,


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the current device must be discarded. As a result, PROMs are also known as one-time

programmable (OTP) devices.

EPROM & EEPROM: An EPROM (erasable-and-programmable ROM) isprogrammed in exactly the same manner as a PROM. However, EPROMs can be erased

and reprogrammed repeatedly. To erase an EPROM, you simply expose the device to a

strong source of ultraviolet light. By doing this, you essentially reset the entire chip to its

initial unprogrammed state. An EEPROM or Electrically Erasable Programmable Read-

Only Memory, is a non-volatile storage chip used in computers and other devices to

store small amounts of volatile (configuration) data. Any byte within an EEPROM may

be erased and rewritten. Once written, the new data will remain in the device forever-or

at least until it is electrically erased. EEPROMs are similar to EPROMs, but the erase

operation is accomplished electrically, rather than by exposure to ultraviolet light.SEEPROM, meaning Serial EEPROM, is an EEPROM chip that uses a serial interface to

the circuit board.

HYBRID MEMORY: As memory technology has matured in recent years, the line

between RAM and ROM has blurred. Now, several types of memory combine features

of both. These devices do not belong to either group and can be collectively referred to

as hybrid memory devices. Hybrid memories can be read and written as desired, like

RAM, but maintain their contents without electrical power, just like ROM. Two of the

hybrid devices, EEPROM and flash, are descendants of ROM devices. These are

typically used to store code. The third hybrid, NVRAM, is a modified version of SRAM.

NVRAM usually holds persistent data.

FLASH MEMORY: Flash memory (sometimes called "flash RAM") is a type of constantly-

powered nonvolatile memory that can be erased and reprogrammed in units of memory called

blocks. It is a variation of EEPROM which, unlike flash memory, is erased and rewritten at

the byte level, which is slower than flash memory updating. Flash memory is often used to

hold control code such as the basic input/output system (BIOS) in a personal computer. When

BIOS needs to be changed (rewritten), the flash memory can be written to in block (rather

than byte) sizes, making it easy to update.


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NVRAM: The third member of the hybrid memory class is NVRAM (non-volatile

RAM). Non-volatility is also a characteristic of the ROM and hybrid memories discussedpreviously. However, an NVRAM is physically very different from those devices. An

NVRAM is usually just an SRAM with a battery backup. When the power is turned on,

the NVRAM operates just like any other SRAM. When the power is turned off, the

NVRAM draws just enough power from the battery to retain its data. NVRAM is fairly

common in embedded systems.

Digital Memory is and has been a close comrade of each and every technical

advancement in Information Technology. The current memory technologies have a lot of

limitations. DRAM is volatile and difficult to integrate. RAM is high cost and volatile. Flash

has slower writes and lesser number of write/erase cycles compared to others. These memory

technologies when needed to expand will allow expansion only two dimensional space.

Hence area required will be increased. They will not allow stacking of one memory chip over

the other. Also the storage capacities are not enough to fulfill the exponentially increasing

need. Hence industry is searching for Holy Grail future memory technologies for portable

devices such as cell phones, mobile PCs etc. Next generation memories are trying a tradeoffs

between size and cost .This make them good possibilities for development.


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3. NEXT GENERATION MEMORIES

Plastic memory is the leading technology among them. It is mainly because of their

expansion capability in three dimensional spaces. The following graph also emphasis

acceptance of Plastic memory. As mentioned earlier microchip makers continue to wring

more and more from silicon, large number of memory technologies were emerged. These

memory technologies are referred as Next Generation Memories. Next Generation

Memories satisfy all of the good attributes of memory. The most important one among them

is their ability to support expansion in three dimensional spaces. Intel, the biggest maker of

computer processors, is also the largest maker of flash-memory chips is trying to combine the

processing features and space requirements feature and several next generation memories arebeing studied in this perspective. They include MRAM, FeRAM, Plastic memory and

Avionics Unified Memory.

Memory Technology Comparison

The graph shows a comparison between cost and speed i.e., the Read/Write time. Disk

drives are faster but expensive where as semiconductor memory is slower in read/write.

Plastic memory lies in an optimum position.

Plastic-based memory modules, as against silicon-based ones, promise to revolutionize

the storage space and memory capabilities of chips. Coatues plastic memory cells are about


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one-quarter the size of conventional silicon cells. And unlike silicon devices, the polymer

cells can be stacked that architecture could translate into memory chips with several times the

storage capacity of flash memory. By 2004, Coatue hopes to have memory chips on the

market that can store 32 gigabits, outperforming flash memory, which should hold about twogigabits by then, to produce a three-dimensional structure.


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4. POLYMERS AS ELECTRONIC MATERIALS

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 tremendousopportunities 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

Films memory technology, polymer solutions can be deposited on flexible substrates with

industry standard processes like spin coating in ultra thin layers.

4.1 Space charge and Polymers:

Making a digital memory device means finding a way to represent the ones and zeros of

computer logic, devising a relatively convenient way to retrieve these binary patterns from

storage, and making sure the information remain stable. 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.


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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. Thesecharges 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.

The researchers made the storage device by spreading a 50-nanometer layer of the

polymer regioregularpoly on glass, then topping it with an aluminum electrode. To write a

space charge to the device, they applied a positive 20-second, 3-volt pulse. To read the state,

they used a 0.2-volt, one minute pulse. Any kind of negative electrical pulse erased this high

state, or charge, replacing it with the default low state. The space charges remain stable for

about an hour and also can be refreshed by another 3-volt positive pulse. The researchers

intend to increase the memory retention ability of their device beyond an hour. Researchers

are looking forward to increasing it into days or more. Once this is achieved, polymer devices

can be used in data storage devices and also as a switch whose state can be changed

externally by a voltage pulse.


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5. PLASTIC COMPUTER MEMORY'S SECRET IS GOLD

NANOPARTICLES

Taiwanese researchers say they have developed a simple, durable, and potentially

inexpensive nonvolatile memory array made from a mix of plastic and gold nanoparticles.

The array is a 16-byte device called an organic nonvolatile bistable memory. The researchers,

from National Chung Hsing University (NCHU) and the quasi-governmental Industrial

Technology Research Institute (ITRI), presented details of the device today in Washington,

D.C., at the 2007 IEEE International Electron Devices Meeting. The Taiwanese team plans to

integrate the memory into smart cards.

Engineers have been pursuing organic nonvolatile memories devices made from plastic

and other carbon-based chemicals because they can potentially be manufactured cheaply

using printing processes. But organic memory devices tend to break down in air and under the

stress of many read-write cycles. Recent measurements suggest that it endures more than

1000 switches and retains its data for roughly 10 days, even when exposed to air. Its stability

may quickly improve, says Pei. Theoretically, the memorys retention time can reach 30

days, he says.
http://www.spectrum.ieee.org/sep07/5487http://www.nchu.edu.tw/New_nchu_3/english/index.phphttp://www.itri.org.tw/eng/index.jsphttp://www.itri.org.tw/eng/index.jsphttp://www.his.com/~iedm/http://www.his.com/~iedm/http://www.itri.org.tw/eng/index.jsphttp://www.itri.org.tw/eng/index.jsphttp://www.nchu.edu.tw/New_nchu_3/english/index.phphttp://www.spectrum.ieee.org/sep07/5487


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The new memory consists of gold nanoparticles mixed into a polymer called PCm,

sandwiched between two aluminum electrodes. Reading the bit stored in the device involves

applying a small voltage and measuring the resulting current.

Ordinarily, the structure conducts little current, the state in which it is storing a 0. But

push the voltage past 2 volts, and the current jumps 10 000-fold. Pei and his colleagues

theorize that before that threshold, a trickle of electrons is hopping from gold nanoparticle to

gold nanoparticle. But some get trapped along the way. At 2 volts, there are so many trapped

electrons that they form a highly conductive path through the device. At that point, smaller

voltages will continue to produce the high current, and the device is considered to be storing a

1. Erasing the bit is simply done by applying a strong negative voltage, sweeping away the

trapped charges.

The voltages involved in writing bits can stress the plastic and make a device unstable by

causing the nanoparticles to clump together. But the Taiwanese researchers found a way to

prevent that by stabilizing the nanoparticles. In the memory device, gold nanoparticles are

connected directly to polymer chains, which act as fingers that get entangled with the host

polymer, says Pei. Therefore, the stabilization of the structure of the organic memory can

be ensured even if high-voltage stress is applied.


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Peis team plans to show off the device on 17 and 18 December at the 2007 International

Symposium for Flexible Electronics and Display (ISFED), to be held in Hsinchu, Taiwan,

and sponsored by ITRI.

An organic memory is considered essential to implement flexible electronics, such as

radio-frequency identification (RFID), smart cards, e-paper, and flexible displays. In mid-

March, ITRI launched Taiwans first laboratory dedicated to flexible electronics, with US

$9.1 million in funding. Other research groups are also pursuing organic nonvolatile memory

devices using either different nanoparticles, such as carbon-60, embedded in the plastic or

using the plastic as part of an organic transistor structure.
http://isfed.itri.org.tw/2007/http://isfed.itri.org.tw/2007/http://www.spectrum.ieee.org/spectrum/sep05/1676http://www.spectrum.ieee.org/spectrum/sep05/1676http://isfed.itri.org.tw/2007/http://isfed.itri.org.tw/2007/


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6. WORKING OF PLASTIC MEMORY

Making a digital memory device means finding a way to represent the ones and zeros of

computer logic, devising a relatively convenient way to retrieve these binary patterns from

storage, and making sure the information remains stable. Plastic memory stores information

in an entirely different manner than silicon devices. Rather than encoding zeroes and ones as

the amount of charge stored in a cell, Coatues chips store data based on the polymers

electrical resistance. Using technology licensed from the University of California, Los

Angeles, and the Russian Academy of Sciences in Novosibirsk, Coatue fabricates each

memory cell as a polymer sandwiched between two electrodes. To activate this cell structure,

a voltage is applied between the top and bottom electrodes, modifying the organic material.

Different voltage polarities are used to write and read the cells.

Application of an electric field to a cell lowers the polymers resistance, thus increasing

its ability to conduct current; the polymer maintains its state until a field of opposite polarity

is applied to raise its resistance back to its original level. The different conductivity States

represent bits of information. A polymer retains space charges near a metal interface when

there is a bias, or electrical current, running across the surface. These charges come eitherfrom 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 device conducts electricity.

The basic principle of Polymer based memory is the dipole moment possessed by

polymer chains. It is the reason by which polymers show difference in electrical conductivity.

As explained earlier implementing a digital memory means setting up away to represent logic

one and logic zero. Here polarizations of polymers are changed up or down to represent logic

one and zero. Now lets see what are a dipole and a dipole moment.

6.1 Dipole Moment:

When electric field is applied to solids containing positive and negative charges, thepositive charges are displaced in the direction of the field towards negative end, while


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negative charges are displaced in the opposite direction. Two equal and opposite charges

separated by a distance form a dipole. Hence this displacement produces local dipoles

throughout the solid. The dipole moment per unit volume of the solid is the sum of all the

individual dipole moments within that volume and is called Polarization of the solid. Theintensity of dipole moment depend on the extend of the displacement which in turn depend on

the applied electric field intensity.

The alignment of local dipoles within a polymer chain

Coatue fabricates each memory cell as a polymer sandwiched between two electrodes.

When electric field is applied polymers local dipoles will set up. The alignment of local

dipoles within a polymer chain is shown in the diagram.


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7. PLASTIC MEMORY TECHNOLOGY

7.1 Basic property of plastic:

While experimenting with a polymer material known as PEDOT, Princeton University

researcher Sven Moller determined that although the plastic conducts electricity at low

voltages, it permanently loses its conductivity when exposed to higher voltages. Together

with colleagues from Hewlett-Packard Laboratories, he developed a method to take

advantage of this property to store digital information, which can be stored as collections of

ones and zeros

7.2 Procedure:

The PEDOT-based memory card consists of a grid of circuits comprising polymer

fuses. A large applied current causes specific fuses to "blow," leaving a mix of functioning

and nonfunctioning connections. When a lower current is later used to read the data, a blown

fuse blocks current flow and is read as a zero, whereas a working fuse is interpreted as a one.

Because the storage method involves a physical change to the device, it is a so-called

WORM--write once, read many times--technology. "The device could probably be made

cheaply enough that one-time use would be the best way to go," says study co-author Stephen

Forrest of Princeton University.

The team predicts that one million bits of information could fit into a square millimeter

of material the thickness of a sheet of paper. A block just a cubic centimeter in size could

contain as many as 1,000 high-quality digital images, the scientists suggest, and producing it

wouldn't require high-temperatures or vacuum chambers.

A two-terminal device in which an organic semiconducting polymer is sandwiched

between two electrodes, indium doped tin oxide (ITO) and aluminum. The experimental

devices contain two polymer layers. The first layer consists of PEDOT: PSS to which an

inorganic salt (e.g. lithium triflate) and plasticizer (ethylene carbonate, EC) have been added.

The second layer consists of poly (3- hexylthiophene) (P3HT) doped with the plasticizer.

Motion of the ions present in the device under influence of an electric field is expected to

induce switching between a high and a low conduction state, the so called ON and OFF state

of a memory device


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Top: Conceptual view of a working device. Application of an electrical voltage to an individual element

blows-out the small polymer fuse, creating a 0. Re-polling of the device records which columns are

1sand which are 0s. Hence a simple but effective memory is created.

Bottom: Schematic of the memory element used in this study, employing an Aluminum coated, flexible

stainless steel substrate. Also shown is the chemical structural formula of the plastic polymer, PEDOT. .

WriteReadErase cycle: A -6V pulse is applied to bring the memory in its writtenstate.

Subsequently the memory is read at -0.5V. Further a +6V pulse is applied to erase to memory.


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A schematic overview of a memory cell.


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The researchers made the storage device by spreading a 50-nanometer layer of the

polymer regioregularpoly on glass, then topping it with an aluminum electrode. To write a

space charge to the device, they applied a positive 20-second, 3-volt pulse. To read the state,

they used a 0.2-volt, one minute pulse. Any kind of negative electrical pulse erased this highstate, or charge, replacing it with the default low state. In this process, a continuous sheet of

flexible polymer is unrolled from one spool, covered with circuit-board-like patterns of

silicon, and collected on another spool.

The Thin Film memory design is solid state, with no mechanical or moving parts

involved. It uses a passively addressed, cross point matrix. An ultra thin layer of the TFE

polymer is sandwiched between two sets of electrodes. A typical array may consist of several

thousand such electrically conducting lines and hence millions of electrode crossings.

Memory cells are defined by the physical overlap of the electrode crossings and selected by

applying voltage. Each electrode crossing represents one bit of information in a true 4f (4-

Lampda square) cell structure, the smallest possible physical memory cell. The effective cell

footprint is further reduced if additional memory layers are applied.

In the latter case, each new layer adds the same capacity as the first one. This stacking is

a fundamental strength of the Thin Film technology. The plastic memory layers are just

1/10,000 of a millimeter or less in thickness, autonomous and easy to deposit. Layer upon

layer may be coated on a substrate. A layer may include a self-contained active memory

structure with on-layer TFT circuitry, or share circuitry with all other layers. Both approaches

offer true 3D memory architecture. The stacking option will enable manufacturers to give

gain previously unattainable storage capacity within a given footprint.


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8. READ/WRITE TECHNOLOGY USED IN PLASTIC

MEMORY

Scientists from Ohio University has created a new spintronics memory device from

plastic. Its simply a thin strip of dark blue organic-based magnet layered with a metallic

ferromagnet and connected to two electrical leads. Still, the researchers successfully recorded

data on it and retrieved the data by controlling the spins of the electrons with a magnetic field.

They say that the new device is a bridge between todays computers and the all -polymer,

spintronic computers that the researchers hope to eventually create.

8.1 Read and write method:To store the memory, the researchers use the wires and the diode surrounding the

PEDOT blob to run either a high or a low current through it. This either creates an

insulator or leaves it as a conductor. To read the memory, they run current through the

top wire and measure the current in the bottom wire. No current means the bit is a zero,

and vice versa. In their paper inNature, the researchers describe just one such junction.

But for a memory application, the device will need many more. So the Hewlett-Packard

team is now working on building a grid of intersecting wires. In this way, they can read

and write multiple bits to one device. A grid system is commonly used in display screens


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to switch individual pixels. Polymer devices can sprayed or printed, and are therefore

much cheaper than silicon devices, which must be etched. Cheap and plastic aren't words

often associated with cutting-edge technology. But researchers in Tokyo have created a

new kind of plastic low-cost flash memory that could find its way into novel flexibleelectronics.

Flash memory stores data electrically, in specially designed silicon transistors.

Information can be recorded and read quickly and is retained even when the power is off.

This makes flash ideal for MP3 players, cameras, memory cards, and USB drives. But the

technology is still more expensive than conventional hard disks.

The prototype plastic flash memory cannot match silicon's storage density, long-term

stability, or number of rewrite cycles. But its low cost could make it possible to integrate flash

memory into more unconventional electronics. For example, cheap plastic memory devices

might be incorporated into e-paper or disposable sensor tags.

8.2 Number of transistors,speed:

NUMBER OF TRANSISTORS:

The stacking also means that a lesser number of transistors can be used for the circuitry in

the chip. The Thin Film system requires about 0.5 million transistors per gigabit of memory

compared to 1.5 to 6.5 billion transistors required by traditional silicon-based systems for one

gigabit. While the illustrations on advantages regarding the size were based on RAM for

matters of convenience, the fact is that the new polymer-based technology can offer total

storage solutions.

SPEED:

The absence of moving parts offers a substantial speed advantage compared to

mechanical storage systems such as magnetic hard disks and optical storage. Thin Film

memory technology is all solid state based. The absence of moving parts in itself offers a

substantial speed advantage compared to all mechanical systems, like magnetic hard disks

and optical systems. The polymer film can be read in two modes either destructive or non-

destructive. In the first case, reading speed is symmetric with write. Depending on how the


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polymer is processed and initialized this speed can range from nanoseconds to microseconds.

This speed symmetry puts the Thin Film memory in a favorable position versus e.g. another

non-volatile memory, NAND flash, where the erase before write may be orders of magnitude

slower than the read. In the non-destructive read mode the Thin Film memory speed will becomparable to or better than DRAM read speeds. More important than single bit speed

capacity is the potentials embedded in the 3D architecture per sec, allowing massive

parallelism in multiple dimensions and the use of mega words rather than the prevailing 64

and 128 bit words.

COST:

Cost-wise, because the polymer is solution-based and can easily be applied to large

surfaces with regular coating processes (even something as simple as printing a photograph

on an ink-jet printer), there is a huge advantage in terms of price for capacity. The use of a

solution based memory material opens up for better price/capacity performance than hitherto

experienced by the electronic industry. For the hybrid silicon-polymer chips, the substrate

circuitry with one memory layer will typically cost the same to process per area unit as

competing silicon devices, however, since more bits can be packaged in that area, the cost per

MB will be substantially lower. The ability to expand capacity by stacking also means that the

cost per MB will reduce substantially. TFE believes that the cost per MB will become so low

that truly disposable memory chips will become possible. One report says that this technology

could take flash card prices to 10 per cent of what they are today.

One can imagine what this would mean to laptops (same footprint, but gigabytes of space

and RAM), mobile phones (more and more phone numbers and SMS messages), PDAs

(more e-mail, more addresses, and more notes), digital cameras (more and better pictures per

card, and the cards are cheap!). The news is explosive: Evidently, for the cost of a few cents, aNorwegian company can produce a memory module with a capacity of up to 170,000

gigabytes, which could fit on a bank card. This price advantage scales with the number of

memory layers. Typically 8 layers involve about the same number of mask steps as making a

conventional memory chip, or twice the cost of a single layer chip, while the storage capacity

increases 8x. Even greater cost advantages will come with TFT based chips, using inkjet

printers or roll-to-roll production. Cost per MB will here become so low that true disposable

memory chips can be envisaged.


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OPERATIONAL TEMPERATURE:

Polymers are robust by nature. The plastic memory developed by Thin Film has

undergone stringent reliability tests at temperatures between -40 and 110C. The results

underline the exceptional stability of the plastic memory and compliance with military andcommercial standard tests.

8.3 Features of plastic memory:

1. Data stored by changing the polarization of the polymer between metal lines.

2. Zero transistors per bit of storage

3. Memory is Nonvolatile

4.Microsecond initial reads.Write speed faster than NAND and NOR Flash.5. Simple processing, easy to integrate with other CMOS

6. No cell standby power or refresh required

7. Operational temperature between -40 and 110C.

8.4 Comparision with plastic memory:

1. Plastic memory is fast. Lab-built devices with a 1GB storage capacity have yielded

read/write cycle times that are 10 times faster than Compact Flash, which are typically 2-

10MB/s read, 1-4MB/s write.

2. It requires far fewer transistors, typically only 0.5M (million) for 1GB of storage

compared to silicon's 1.5-6.5B (billion).

3. It costs about 5% as much to manufacture compared to silicon based memory.

4. It can be stacked vertically in a product, yielding 3D space usage; silicon chips can

only be set beside each other.

5. It has very low power consumption.6. The control circuitry only occupies 1-5% of total transistor area.

7. It maintains memory even when the power is turned off. Nothing new compared to flash,

but worth mentioning.

8.5 Advantages of plastic memory:

The plastic memory technology promises to store more data at less cost than the

Expensive to build silicon chips used by popular consumer gadgets including digital


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cameras, cell phones and portable music players.

The memory cannot be rewritten, but can be read very fast and with the low power

consumption. So this would be suitable only for permanent storage.

Unlike flash memory found in consumer devices, the new technology can be written toonly once, though it can be read many times. It acts in that respect like a non re-writeable

compact disc. But this new memory, which retains data even when there's no power,

won't require a power-hungry laser or motor to read or write, and promises more capacity.

PEDOT-based machine could solve the problem of virus hackers, who rely on the fact

they cannot afford to leave a trace out of fear of being caught for their dirty work.

With PEDOT-based solutions, hackers would not be able to erase their IP addresses.

Instead of rewriting over existing data, PEDOT would just create a static section for

incoming data. This ensures that the integrity of data on documents is preserved over long

periods of time.

8.6 Limitations of plastic memory:

The dimension demands on devices increasingly get smaller to host a variety of form

factors. Smaller memory space means the transistors leak more electricity and suck

up more power. It can be read many times but it can be write only ones. The biggest challenge is

developing production technique. This technology is still under research, so it will take

about 5yrs to launch in the market.

But turning plastic memory into a commercial product wont be easy. Memory

technologies compete not only on storage capacity but on speed, energy consumption and

reliability. The difficulty is in meeting all the requirements of current silicon memory

chips. The plastic memory made at Bell Labs is still relatively slow by silicon standards,

and anticipated capacity is only on the order of a kilobit.

8.7Applications of plastic memory:

Flash memory stores data electrically, in specially designed silicon transistors.

Information can be recorded and read quickly and is retained even when the power is off.

This makes flash ideal for MP3 players, cameras, memory cards, and USB drives.


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The plastic memory technology promises to store more data at less cost than the

expensive-to-build silicon chips used by popular consumer gadgets including digital

cameras, cell phones and portable music players.

The memory cannot be rewritten, but can be read very fast and with low powerconsumption. So this would be suitable only for permanent storage.

Unlike flash memory found in consumer devices, the new technology can be written

to only once, though it can be read many times. It acts in that respect like a non-

rewriteable compact disc. But this new memory, which retains data even when

there's no power, won't require a power-hungry laser or motor to read or write, and

promises more capacity.

PEDOT-based machine could solve the problem of virus hackers, who rely on the

fact they cannot afford to leave a trace out of fear of being caught for their dirty

work.

With PEDOT-based solutions, hackers would not be able to erase their IP addresses.

Instead of rewriting over existing data, PEDOT would just create a static section for

incoming data. This ensures that the integrity of data on documents is preserved over

long periods of time.

Polymer devices can be used in data storage devices and also as a switch whose state

can be changed externally by a voltage pulse.


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9. FUTURE SCOPE

Cost per MB will here become so low that true disposable memory chips can be

envisaged. One report says that this technology could take flash card prices to 10 per cent of

what they are today. By 2004, Coatue hopes to have memory chips on the market that can

store 32 gigabits, outperforming flash memory, which should hold about two gigabits by then,

to produce a three-dimensional structure.

One can imagine what this would mean to laptops (same footprint, but gigabytes of space

and RAM), mobile phones (more and more phone numbers and SMS messages), PDAs

(more e-mail, more addresses, and more notes), digital cameras (more and better pictures per

card, and the cards are cheap!). Evidently, for the cost of a few cents, a Norwegian company

can produce a memory module with a capacity of up to 170,000 gigabytes, which could fit on

a bank card.

One likely use is in disposable electronics, where cost, rather than performance, is the

deciding factor. Researchers at Lucent Technologies Bell Laboratories are working on

plastic memory devices for use in identification tags.

As plastic memory technology advances, it could pave the way to computers made

entirely of plastic electronic components, from the display to the logic chip. That may be

decades off, but as researchers push the bounds of polymers, the vision seems less far-fetched.

9.1Goal of plastic memory:

The goal is to make the technology fast enough to store video. The researchers hope

that this technology will decrease the size, increase reliability and speed up reading and

writing of memory chips.


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10. CONCLUSION

The fundamental strength i.e., the stacking of memory layers which yields maximum

storage capacity in a given footprint is the main reason why Plastic memory is highly

preferred. The non-volatileness and other features are in built in molecular level and offers

very high advantages in terms of cost. Polymers ,which are once considered to be the main

reason for pollution and referred to be removed from the earth, has found a new area of

utilization.

Plastic memory is much cheaper and faster than the existing silicon a circuit was

invented by Researchers at Princeton University working with Hewlett- Packard. Plastic

memory is a combination of materials that could lower the cost and boost the density of

electronic memory. It is an all-organic memory system with manifold advantages: in

speed, production, energy consumption, storage capacity and cost. The memory cannot

be rewritten, but can be read very fast and with low power consumption. So this would

be suitable only for permanent storage.


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11. REFERENCES

1. A. Lendlein and S. Kelch, "Shape-Memory Polymer". Angew. Chem. Int. Ed., WILEY,

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3. M.Ishii, Development of shape-memory polymers; M. Irie, Eds. CMC, Tokyo, 2000, pp. 10-

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4. Y. Chujo, K. Sada, and T. Saegusa, "Reversible Gelation of Polyoxazoline by Means of

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http://dx.doi.org/10.1021/ma00212a007http://dx.doi.org/10.1126/science.1065879http://dx.doi.org/10.1126/science.1065879http://dx.doi.org/10.1021/ma00212a007

60545320 plastic memory report

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