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Dept of E.C.E. B.I.T.Institute of Technology 1

List of Figures

Abbreviations

Notations

Chapter no. Title Pg no.

1. 1.1 Introduction 11.2 History 2

1.3 Need for Memristor 4

1.4 Memristor- Fourth Basic Circuit Element 6

1.5 Types of Memristors 71.6 Titanium Dioxide Memristor 8

2. ` 2.1 Memristor Theory 10

2.1.1 Definition of Memristor 10

2.1.2 Memristance 10

2.1.3 Theory 10

2.2 Current Voltage Characteristics 11

2.3Working 14

3 3.1 Potential Applications 16

3.1.1 Replacement of DRAM 16

3.1.2Brain- Like Systems 16

3.1.3Nano- Scale Electronics 17

3.1.4 Operation as a switch 17

3.1.5 Computer like Human Brain 18

3.1.6 Memristor Chips 19

3.1.7 Digital & Analog 20

3.1.8No need of Rebooting 20

3.2 Features 20

3.3 Disadvantages 21

3.4 Future of Memristor 22

3.5 When it is coming 22

4 4.1 Conclusion 24

4.2 Bibliography 25

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LIST OF FIGURES

Fig. No. Title Page No.

1.1 REALIZATION OF FOUR ELEMENT CHUASCIRCUIT3

1.2 THE SIMPLEST CHUAS CIRCUIT...3

1.3 SHOWING MEMRISTOR AS FOURTH BASIC ELEMENT...4

1.4 FUNDAMENTAL CIRCUIT ELEMENTS AND VARIABL.....5

1.5 MICROSCOPE IMAGE OF A SIMPLE CIRCUIT

WITH 17 MEMRISTORS LINED UP IN A ROW...9

2.1 SYMBOL OF MEMRISTOR...10

2.2 CURRENT VS. VOLTAGE CURVE DEMONSTRATING

HYSTERETIC EFFECTS OF MEMRISTANCE...12

2.3 IDEALIZED HYSTERESIS MODEL OF RESISTANCE

VS VOLTAGE FOR MEMRISTANCE SWITCH.....12

2.4 MEMRISTOR MODEL.......13

2.5 AL/TIO2 OR TIOX /AL SANDWICH .....14

2.6 SHOWING 17 MEMRISTORS IN A ROW.15

3.1 BRAIN LIKE SYSTEM....16

3.2 MEMRISTOR (AG+SI).. 21

3.3 HP MEMRISTOR.....23

3.4 PRACTICAL TITANIUM DIOXIDE MEMRISTOR......23

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ABSTRACT

Typically electronics has been defined in terms of

three fundamental elements such as resistors, capacitors and inductors. These

three elements are used to define the four fundamental circuit variables which

are electric current, voltage, charge and magnetic flux. Resistors are used to

relate current to voltage, capacitors to relate voltage to charge, and

inductors to relate current to magnetic flux, but there was no element which

could relate charge to magnetic flux.

To overcome this missing link, scientists came up with a newelement called Memristor. These Memristor has the properties of both a memory

element and a resistor (hence wisely named as Memristor). Memristor is being

called as the fourth fundamental component, hence increasing the importance

of its innovation

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1.1 INTRODUCTION :

Generally when most people think about electronics, they may initially think of

products such as cell phones, radios, laptop computers, etc. others, having some

engineering background, may think of resistors, capacitors, etc. which are the basic

components necessary for electronics to function. Such basic components are fairly

limited in number and each having their own characteristic function.Memristor theory was formulated and named by Leon Chua in a 1971

paper. Chua strongly believed that a fourth device existed to provide conceptual

symmetry with the resistor, inductor, and capacitor. This symmetry follows from the

description of basic passive circuit elements as defined by a relation between two of the

four fundamental circuit variables. A device linking charge and flux (they a r e defined

as time integrals of current and voltage), which would be the memristor, was still

hypothetical at the time.

However, it would not be until thirty-seven years later, on April 30, 2008, that

a team at HP Labs led by the scientist R. Stanley Williams would announce the

discovery of a switching memristor. Based on a thin film of titanium dioxide, it hasbeen presented as an approximately ideal device.

The reason that the memristor is radically different from the other fundamental

circuit elements is that, unlike them, it carries a memory of its past. When you turn off

the voltage to the circuit, the memristor still remembers how much was applied before

and for how long. That's an effect that can't be duplicated by any circuit combination of

resistors, capacitors, and inductors, which is why the memristor qualifies as a

fundamental circuit element. The arrangement of these few fundamental circuit

components form the basis of almost all of the electronic devices we use in our

everyday life. Thus the discovery of a brand new fundamental circuit element is

something not to be taken lightly and has the potential to open the door to a

brand new type of electronics. HP already has plans to implement Memristors in

a new type of non-volatile memory which could eventually replace flash and other

memory systems.

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1.2 HISTORY

The transistor was invented in 1925 but lay dormant until finding a

corporate champion in Bell Labs during the 1950s. Now another groundbreakingelectronic circuit may be poised for the same kind of success after laying

dormant as an academic curiosity for more than three decades. Hewlett-

Packard Labs is trying to bring the memristor, the fourth passive circuit

element after the resistor, and the capacitor the inductor into the

electronics mainstream.

Postulated in 1971, the memory resistor represents a potential

revolution in electronic circuit theory similar to the invention of transistor. The

history of the memristor can be traced back to nearly four decades ago when in

1971, Leon Chua, a University of California, Berkeley, engineer predicted that

there should be a fourth passive circuit element in addition to the other three

known passive elements namely the resistor, the capacitor and the inductor. He

called this fourth element a memory resistor or a memristor.

Examining the relationship between charge, current, voltage and flux in

resistors, capacitors, and inductors in a 1971 paper, Chua postulated the existence

of memristor. Such a device, he figured, would provide a similar relationship

between magnetic flux and charge that a resistor gives between voltage and

current. In practice, that would mean it acted like a resistor whose value could

vary according to the current passing through it and which would remember

that value even after the current disappeared.

But the hypothetical device was mostly written off as a mathematical

dalliance. However, it took more than three decades for the memristor to be

discovered and come to life. Thirty years after Chuas Proposal of this

mysterious device, HP senior fellow Stanley Williams and his group were

working on molecular electronics when they started to notice strange behavior

in their devices. One of his HP collaborators, Greg Snider, then rediscovered

Chua's work from 1971. Williams spent several years reading and rereading

Chua's papers. It was then that Williams realized that their molecular devices

were really Memristors.

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FIG 1.1: REALIZATION OF FOUR ELEMENT CHUAS CIRCUIT

FIG 1. 2: THE SIMPLEST CHUAS CIRCUIT

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FIG 1.3: SHOWING MEMRISTOR AS FOURTH BASIC ELEMENT

1.3 NEED FOR MEMRISTOR

A memristor is one of four basic electrical circuit components,

joining the resistor, capacitor, and inductor. The memristor, short for

memory resistor was first theorized by student Leon Chua in the early

1970s. He developed mathematical equations to represent the memristor, which

Chua believed would balance the functions of the other three types of circuit

elements.

The known three fundamental circuit elements as resistor, capacitor and

inductor relates four fundamental circuit variables as electric current, voltage,

charge and magnetic flux. In that we were missing one to relate charge to

magnetic flux. That is where the need for the fourth fundamental element

comes in. This element has been named as memristor.

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FIG 1.4: FUNDAMENTAL CIRCUIT ELEMENTS AND VARIABLES.

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1.4 MEMRISTOR-THE FOURTH BASIC CIRCUIT ELEMENT

What Are Memristors?

What is a memristor? Memristors are basically a fourth class of electricalcircuit, joining the resistor, the capacitor, and the inductor, that exhibit their

unique properties primarily within the nanoscale. Theoretically, Memristors, a

concatenation of memory resistors, are a type of passive circuit elements

that maintain a relationship between the time integrals of current and voltage

across a two terminal element. Thus, a Memristors resistance varies

according to a devices memristance function.

Until recently, when HP Labs under Stanley Williams developed the

first stable prototype, memristance as a property of a known material was

nearly nonexistent. The memristance effect at non-nanoscale distances is

dwarfed by other electronic and field effects, until scales and materials that

are nanometers in size are utilized. At the nanoscale, such properties have even

been observed in action prior to the HP Lab prototypes.

But beyond the physics of electrical engineering, they are a

reconceptualizing of passive electronic circuit theory first proposed in 1971 by

the nonlinear circuit theorist Leon Chua. What Leon Chua, a UC Berkeley

Professor contended in his 1971 paper Transactions on Circuit Theory, is that

the fundamental relationship in passive circuitry was not between voltage and

charge as assumed, but between changes-in-voltage, or flux, and charge. Chua

has stated: The situation is analogous to what is called Aristotles Law of

Motion, which was wrong, because he said that force must be proportional to

velocity. That misled people for 2000 years until Newton came along and

pointed out that Aristotle was using the wrong variables. Newton said that force

is proportional to accelerationthe change in velocity. This is exactly the situation

with electronic circuit theory today. All electronic textbooks have been

teaching using the wrong variablesvoltage and chargeexplaining away

inaccuracies as anomalies. What they should have been teaching is the

relationship between changes in voltage, or flux, and charge.

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1.5 TYPES OF MEMRISTORS:

Spintronic Memristor Spin Torque Transfer Magneto resistance Titanium dioxide memristor Polymeric memristor Spin memristive systems Magnetite memristive systems

Resonant tunneling diode memristor

Titanium Dioxide Memristor It is a solid state device that uses nano

scale thin-films to produce a Memristor. The device consists of a thin titanium

dioxide film (50nm) in between two electrodes (5nm) one Titanium and the

other latinum. Initially, there are two layers to the titanium dioxide film,

one of which has a slight depletion of oxygen atoms. The oxygen

vacancies act as charge carriers and this implies that the depleted layer has

a much lower resistance than the no depleted layer. When an electric field is

applied, the oxygen vacancies drift, changing the boundary between the high-

resistance and low-resistance layers. Thus the resistance of the film as a whole

is dependent on how much charge has been passed through it in a particular

direction, which is reversible by changing the direction of current.

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1.6 TITANIUM DIOXIDE MEMRISTOR

Interest in the memristor revived in 2008 when an experimental solid

state version was reported by R. Stanley Williams of Hewlett Packard. A

solid-state device could not be constructed until the unusual behavior of

nanoscale materials was better understood. The device neither uses magnetic

flux as the theoretical memristor suggested, not stores charge as a capacitor

does, but instead achieves a resistance dependent on the history of current

using a chemical mechanism.

The HP device is composed of a thin (5 nm) titanium dioxide film

between two electrodes. Initially, there are two layers to the film, one of

which has a slight depletion of oxygen atoms. The oxygen vacancies act as

charge carriers, meaning that the depleted layer has a much lower resistance than

the non-depleted layer. When an electric field is applied, the oxygen vacancies

drift (see Fast ion conductor), changing the boundary between the high-resistance

and low-resistance layers. Thus the resistance of the film as a whole is

dependent on how much charge has been passed through it in a particular

direction, which is reversible by changing the direction of current. Since the

HP device displays fast ion conduction at nanoscale, it is considered a

nanoionic device.

Memristance is only displayed when the doped layer and depleted layer

both contribute to resistance. When enough charge has passed through the

memristor that the ions can no longer move, the device enters hysteresis. It

ceases to integrate q=Idt but rather keeps q at an upper bound and M fixed,

thus acting as a resistor until current is reversed.

Memory applications of thin-film oxides had been an area of active

investigation for some time. IBM published an article in 2000 regarding

structures similar to that described by Williams. Samsung has a pending U.S.

patent application for several oxide-layer based switches similar to that described

by Williams.

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Although the HP memristor is a major discovery for electrical

engineering theory, it has yet to be demonstrated in operation at practical

speeds and densities. Graphs in Williams original report show switching

operation at only ~1 Hz. Although the small dimension of the device seem to

imply fast operation, the charge carriers move very slowly, with an ion mobility

of 10-10

cm2 /(Vs). In comparison, the highest known drift ionic mobilities

occur in advanced superionic conductors, such as rubidium silver iodide with

about 2x10-4

cm/(Vs) conducting silver ions at room temperature. Electrons

and holes in silicon have a mobility ~1000 cm/(Vs), a figure which is essential

to the performance of transistors. However, a relatively low bias of 1 volt was

used, and the plots appear to be generated by a mathematical model ratherthan a laboratory experiment

FIG 1.5: MICROSCOPE IMAGE OF A SIMPLE CIRCUIT WITH 17 MEMRISTORS LINED UPIN A ROW

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CHAPTER - 2

2.1 MEMRISTOR THEORY AND ITS PROPERTIES:

2.1.1 Definition of Memristor

The memristor is formally defined as a two-terminal element in

which the magnetic flux m between the terminals is a function of the amount

of electric charge q that has passed through the device.

FIG 2.1 : SYMBOL OF MEMRISTOR.

Chua defined the element as a resistor whose resistance level was based

on the amount of charge that had passed through the memristor

2.1.2 Memristance

Memristance is a property of an electronic component to retain its

resistance level even after power had been shut down or lets it remember (or

recall) the last resistance it had before being shut off.

2.1.3 Theory

Each memristor is characterized by its memristance function

describing the charge- dependent rate of change of flux with charge.

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Noting from Faraday's law of induction that magnetic flux is simply the

time integral of voltage, and charge is the time integral of current, we may write

the more convenient form

It can be inferred from this that memristance is simply charge-dependent

resistance. . i.e. ,

V(t) = M(q(t))*I(t)

This equation reveals that memristance defines a linear relationship

between current and voltage, as long as charge does not vary. Of course,

nonzero current implies instantaneously varying charge. Alternating current,

however, may reveal the linear dependence in circuit operation by inducing

a measurable voltage without net charge movement as long as the

maximum change in q does not cause much change in M.

2.2CURRENT VS. VOLTAGE CHARACTERISTICS

This new circuit element shares many of the properties of resistors and

shares the same unit of measurement (ohms). However, in contrast to ordinary

resistors, in which the resistance is permanently fixed, memristance may be

programmed or switched to different resistance states based on the history of the

voltage applied to the memristance material. This phenomenon can be

understood graphically in terms of the relationship between the current

flowing through a memristor and the voltage applied across the memristor.

In ordinary resistors there is a linear relationship between current and

voltage so that a graph comparing current and voltage results in a straight line.

However, for Memristors a similar graph is a little more complicated as shown

in Fig. 3 illustrates the current vs. voltage behavior of memristance.

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In contrast to the straight line expected from most resistors the behavior

of a memristor appear closer to that found in hysteresis curves associated with

magnetic materials. It is notable from Fig. 3 that two straight line segments are

formed within the curve. These two straight line curves may be interpreted as

two distinct resistance states with the remainder of the curve as transition

regions between these two states.

FIG 2.2: CURRENT VS. VOLTAGE CURVE DEMONSTRATING HYSTERETIC EFFECTS OFMEMRISTANCE.

Fig. 4 illustrates an idealized resistance behavior demonstrated in

accordance with Fig. 3 wherein the linear regions correspond to a relatively high

resistance (RH) and low resistance (RL) and the transition regions are represented

by straight lines.

FIG 2.3: IDEALIZED HYSTERESIS MODEL OF RESISTANCE VS. VOLTAGE FOR MEMRISTANCE

SWITCH.

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Thus for voltages within a threshold region (-VL2

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WORKING OF MEMRISTOR

FIG 2.5 : AL/TIO2 OR TIOX /AL SANDWICH

The memristor is composed of a thin (5 nm) titanium dioxide film

between two electrodes as shown in figure 5(a) above. Initially, there are two

layers to the film, one of which has a slight depletion of oxygen atoms. The

oxygen vacancies act as charge carriers, meaning that the depleted layer has amuch lower resistance than the non-depleted layer. When an electric field is

applied, the oxygen vacancies drift changing the boundary between the high-

resistance and low-resistance layers.

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FIG 2.6 : SHOWING 17 MEMRISTORS IN A ROW

Thus the resistance of the film as a whole is dependent on how much

charge has been passed through it in a particular direction, which is reversible by

changing the direction of current. Since the memristor displays fast ion

conduction at nanoscale, it is considered a nanoionic device.

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CHAPTER3

3.1 POTENTIAL APPLICATIONS

3.1.1 Replacement for DRAM

Computers using conventional D-RAM lack the ability to retain

information once they are turned off. When power is restored to a D-RAM-based

computer, a slow, and energy-consuming boot-up" process is necessary to

retrieve data stored on a magnetic disk required to run the system. the reason

computers have to be rebooted every time they are turned on is that their logic

circuits are incapable of holding their bits after the power is shut off. But

because a memristor can remember voltages, a memristor-driven computer would

arguably never need a reboot. You could leave all your Word files and

spreadsheets open, turn off your computer, and go get a cup of coffee or go on

vacation for two weeks

3.1.2 Brain-like systems

FIG 3.1 :BRAIN LIKE SYSTEM

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As for the human brain-like characteristics, memristor technology could

one day lead to computer systems that can remember and associate patterns in a

way similar to how people do. This could be used to substantially improve facial

recognition technology or to provide more complex biometric recognition

systems that could more effectively restrict access to personal information.

These same pattern-matching capabilities could enable appliances that learn

from experience and computers that can make decisions.

3.1.3 Memristors for Nanoscale electronics

The main objective in the electronic chip design is to move

computing beyond the physical and fiscal limits of conventional silicon

chips. For decades, increases in chip performance have come about largely

by putting more and more transistors on a circuit. Higher densities, however,

increase the problems of heat generation and defects and affect the basic

physics of the devices.

Instead of increasing the number of transistors on a circuit, we could create

a hybrid circuit with fewer transistors but with the addition of Memristors which

could add functionality. Alternately, memristor technologies could enable moreenergy-efficient high-density circuits.

3.1.4 Operation as a switch

For some Memristors, applied current or voltage will cause a great change in

resistance. Such devices may be characterized as switches by investigating the time

and energy that must be spent in order to achieve a desired change in resistance.

Here we will assume that the applied voltage remains constant and solve for the

energy dissipation during a single switching event.

For a memristor to switch from Ron to Roff in time Ton to Toff, the charge mustchange by

Q=Qon-Qoff.

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The middle expression results from changing the variable of

integration, and the final expression reflects W/I = 1/V. This power

characteristic differs fundamentally from that of a metal oxide semiconductor

transistor, which is a capacitor-based device. Unlike the transistor, the final

state of the memristor in terms of charge does notdepend on bias voltage.

The type of memristor described by Williams ceases to be ideal after

switching over its entire resistance range and enters hysteresis, also called the

"hard-switching regime." Another kind of switch would have a cyclic M(q) so

that each off-on event would be followed by an on-offevent under constant bias.

Such a device would act as a memristor under all conditions, but would be less

practical.

3.1.5 New 'Memristor' Could Make Computers Work like Human Brains

After the resistor, capacitor, and inductor comes the memristor.

Researchers at HP Labs have discovered a fourth fundamental circuit element that

can't be replicated by a11 combination of the other three. The memristor (short for

"memory resistor") is unique because of its ability to, in HP's words, "[retain] a

history of the information it has acquired." HP says the discovery of the

memristor paves the way for anything from instant on computers to systems

that can "remember and associate series of events in a manner similar to

the way a human brain recognizes patterns." Such brain-like systems

would allow for vastly improved facial or biometric recognition, and they

could be used to make appliances that "learn from experience."

In PCs, HP foresees Memristors are being used to make new types of

system memory that can store information even after they lose power, unlike

today's DRAM. With memristor-based system RAM, PCs would no longer need

to go through a boot process to load data from the hard drive into the memory,

which would save time and power especially since users could simply switch

off systems instead of leaving them in a "sleep" mode.

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3.1.6 Memristors Make Chips Cheaper

The first hybrid memristor-transistor chip could be cheaper and more

energy efficient. Entire industries and research fields are devoted to ensuring

that, every year, computers continue getting faster. But this trend could begin

to slow down as the components used in electronic circuits are shrunk to the

size of just a few atoms. Researchers at HP Labs in Palo Alto, CA, are betting

that a new fundamental electronic component--the memristor--will keep

computer power increasing at this rate for years to come.

They are nanoscale devices with unique properties: a variable resistance

and the ability to remember the resistance even when the power is off.

Increasing performance has usually meant shrinking components so that more

can be packed onto a circuit. But instead, Williams team removes some

transistors and replaces them with a smaller number of Memristors. "We're

not trying to crowd more transistors onto a chip or into a particular circuit,"

Williams says. "Hybrid memristor-transistor chips really have the promise for

delivering a lot more performance." A memristor acts a lot like a resistor but

with one big difference: it can change resistance depending on the amount

and direction of the voltage applied and can remember its resistance even when

the voltage is turned off. These unusual properties make them interesting from

both a scientific and an engineering point of view. A single memristor can

perform the same logic functions as multiple transistors, making them a

promising way to increase computer power. Memristors could also prove to

be a faster, smaller, more energy-efficient alternative to flash storage.

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3.1.7 Memristor as Digital and AnalogA memristive device can function in both digital and analog forms,

both having very diverse applications. In digital mode, it could substitute

conventional solid-state memories (Flash) with high-speed and less steeply

priced nonvolatile random access memory (NVRAM).

Eventually, it would create digital cameras with no delay between photos

or computers that save power by turning off when not needed and then turning

back on instantly when needed.

3.1.8 No Need of Rebooting

The memristor's memory has consequences: The reason computers have

to be rebooted every time they are turned on is that their logic circuits are

incapable of holding their bits after the power is shut off. But because a

memristor can remember voltages, a memristor-driven computer would

arguably never need a reboot. You could leave all your Word files and

Spread sheets open, turn off your computer, and go get a cup of coffee or go on

vacation for two weeks, says Williams. When you come back, you turn on

your computer and everything is instantly on the screen exactly the way you

left it. That keeps memory powered. HP says memristor-based RAM could

one day replace DRAM altogether.

3.2 FEATURES

The reason that the memristor is radically different from the other

fundamental Circuit elements is that, unlike them, it carries a memory of its past.

When you turn off the voltage to the circuit, the memristor still remembers how

much was applied before and for how long. That's an effect that can't be

duplicated by any circuit combination of resistors, capacitors, and inductors,

which is why the memristor qualifies as a fundamental circuit element.

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FIG 3.2 : MEMRISTOR (AG+SI)

3.3 DISADVANTAGES

Physical restrictions on M(q)

An applied constant voltage potential results in uniformly increasing

m. numerically, infinite memory resources, or an infinitely strong field,

would be required to store a number which grows arbitrarily large. Three

alternatives avoid this physical impossibility:

M(q) approaches zero, such that m = M(q)dq = M(q(t))I dt remainsbounded but continues changing at an ever-decreasing rate. Eventually, this

would encounter some kind of quantization and unideal behavior.

M(q) is cyclic, so thatM(q) =M(q- q) for all qand some q, e.g. sin2(q/Q). The device enters hysteresis once a certain amount of charge has passed

through, or otherwise ceases to act as a memristor.

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3.4 FUTURE OF MEMRISTOR

Although memristor research is still in its infancy, HP Labs is working

on a handful of practical memristor projects. And now Williams team has

demonstrated a working memristor-transistor hybrid chip. "Because

Memristors are made of the same materials used in normal integrated

circuits," says Williams, "it turns out to be very easy to integrate them

with transistors." His team, which includes HP researcher Qiangfei Xia, built a

field-programmable gate array (FPGA) using a new design that includes

Memristors made of the semiconductor titanium dioxide and far fewer

transistors than normal. Engineers commonly use FPGAs to test prototype chip

designs because they can be reconfigured to perform a wide variety of different

tasks. In order to be so flexible, however, FPGAs are large and expensive. And

once the design is done, engineers generally abandon FPGAs for leaner"application-specific integrated circuits."."When you decide what logic

operation you want to do, you actually flip a bunch of switches and

configuration bits in the circuit," says Williams. In the new chip, these tasks are

performed by Memristors. "What we're looking at is essentially pulling out all

of the configuration bits and all of the transistor switches," he says. According to

Williams, using Memristors in FPGAs could help significantly lower costs. "If

our ideas work out, this type of FPGA will completely change the balance," he

says. Ultimately, the next few years could be very important for memristor

research. Right now, "the biggest impediment to getting Memristors in the

marketplace is having [so few] people who can actually design circuits [usingMemristors]," Williams says. Still, he predicts that Memristors will arrive in

commercial circuits within the next three years.

3.5 WHEN IS IT COMING?

Researchers say that no real barrier prevents implementing the

memristor in circuitry immediately. But it's up to the business side to push

products through to commercial reality. Memristors made to replace flashmemory (at a lower cost and lower 14 power consumption) will likely appear

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first; HP's goal is to offer them by 2012. Beyond that, Memristors will likely

replace both DRAM and hard disks in the 2014-to-2016 time frame. As for

memristor-based analog computers, that step may take 20-plus years.

FIG 3.3 : HP MEMRISTOR

FIG 3.4 : PHOTO OF A PRACTICAL TITANIUM DIOXIDE MEMRISTOR

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CHAPTER4

4.1 CONCLUSION

In this paper, i have demonstrated the possibility of using memristor.

By redesigning certain types of circuits to include Memristors, it is possible to

obtain the same function with fewer components, making the circuit itself less

expensive and significantly decreasing its power consumption. In fact, it can be

hoped to combine Memristors with traditional circuit-design elements to

produce a device that does computation. The Hewlett-Packard (HP) group is

looking at developing a memristor-based nonvolatile memory that could be

1000 times faster than magnetic disks and use much less power. The main

conclusion is that Memristors will likely replace both DRAM and hard disks in

the future.

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4.2BIBLIOGRAPHY

Lee-Eun Yu, Sungho Kim, Min-Ki Ryu, Sung-Yool Choi and Yang-KyuChoi, Structure Effects on Resistive Switching of Al/TiOx/Al Devices forRRAM Applications, IEEE ELECTRON DEVICE LETTER, VOL. 29, NO. 4,APRIL 2008

Chih-Yang Lin, Chih-Yi Liu, Chun-Chieh Lin, T.Y, Tseng, Currentstatus of resistive nonvolatile memories/Memristors, J Electroceram, DOI10.1007/s10832-007-9081-y,2007.

R. Colin Johnson ,HP reveals memristor ,the forth passive circuit

element, by Information week magazine on April30,2008.

http://blogs.spectrum.ieee.org/tech_talk/2008/07/Memristors_coming_soon_to_a_br.html

http://www.memristor.org/
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