MEMRISTOR

PRESENTED BY DESAI MAHADEV V.

(ROLLNO.37)

UNDER GUIDANCE OF PROF.MR.DODABHANGI S.B.

The Next Revolution In Technology

OVERVIEWOVERVIEW

WHAT IS MEMRISTOR HISTORY OF MEMRISTOR EXISTING TECHNOLOGY WORKING OF MEMRISTOR PROPERTY OF MEMRISTOR BENEFITS OF MEMRISTOR FUTURE ADVANTAGE OF MEMERISTOR MAJOR CHALLENGES CONCLUSION REFERENCES

What is memristor ?

What is memristor ?

MEMRISTOR

Memristor

Memory Resistor+

Memristor

Memristor can be defined as a two

terminal device which shows the

relation between magnetic flux

and charge

MEMRISTOR SYMBOL

Definition of Memristor

• A Memristor is a semiconductor whose resistance varies as a function of flux and charge. This allows it to “remember” what has passed through the circuit.

• Characterized by Memristance

• Memristance is simply charge-dependent resistance. V(t) = M(q(t))*I(t)

• Unit - ohm (Ω)

• Symbol

The term Memristor was first proposed by Leon Chua in 1971when he was a rising

professor atThe University of CaliforniaThe University of California

Berkeley

LEON.O.CHUA

Three Fundamental Circuit Elements

Resistor

v R i

Capacitor

q C v

Inductor

L i

ResistorGeorg Ohm 1827

Capacitorvon Kleist 1745

InductorMichael Faraday 1831

The Missing Circuit Element

Voltage (V)

Current(i)

Charge (q)

Flux (Φ)

Φ = Li Inductors

??

v=dΦ/dt i=dq/dt

Resistors v=Ri

q=CvCapacitors

Memristor 1971

MemristorsΦ=Mq

Voltage (V)

Current(i)

Charge (q)

Flux (Φ)

Φ = Li Inductors

v=dΦ/dt i=dq/dt

Resistors v=Ri

q=CvCapacitors

WORKING

Applied voltage makes the oxygen vacancies (+ve) to shift towards the –ve voltage

PT PTTiOv(2-x)

TiO2

3 nm

2 nm

OxidizedReduced

(-)ve (+)ve

The HP device is composed of a thin (50 nm) titanium dioxide film between two 5 nm thick electrodes, one Ti, the other Pt. 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, 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 ,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 as a nanoionic device.

Analogy Of Memristor

A RESISTOR WITH MEMORY BEHAVES LIKE A PIPE

• The diameter of pipe remains same when the current is switched off, until it is switched on again.

• The pipe, when the current is switched on again, remembers what current has flowed through it.

What Sets Memristor Apart ??• Conventional devices use only 0 and 1; Memristor can

use anything between 0 and 1.

• Faster than Flash memory.– Allow digital cameras to take pictures with no delay in

between.

• Innovating nanotechnology due to the fact that it performs better the smaller it becomes.

• Retain its resistance level even after power had been shut down.

• Remember (or recall) the last resistance it had, before being shut off.

• By changing the speed and strength of the current, it is possible to change the behavior of the device.

• A fast and hard current causes it to act as a digital device.

• A soft and slow current causes it to act as an analog device.

Property Of Memristor

Is it analog or digital?

Amazingly, its both.

Benefits Of Memristor Technology

• Would allow for a quicker boot up since information is not lost when the device is turned off.

• Uses less energy and produces less heat.

• Eliminates the need to write computer programs that replicate small parts of the brain.

• Creating a Computer that never has to boot up.

• Does not lose information when turned off.

• Density allows for more information to be stored.

• Has the capacity to remember the charge that flows through it at a given point in time.

Future Technological Significance

• Pattern recognition and learning.

• Crossbar latches to replace transistors.

• New forms signal processing and control systems.

• Memristors can be used to do digital logic using implication instead of NAND.

• Could lead to replacement of the transistor

• No more hard drive and RAM

• Just Memristors

• Very high storage and speeds.

Nonvolatile memoriesNonvolatile memories

Booting free computers

ADVANTAGES

• Provides greater resiliency and reliability when power is interrupted in data centers.

• Density allows for more information to be stored.

• Power Consumption As non-volatile memory, memristor do not

consume power when idle.

MAJOR CHALLNGES

• The memristor major challenges are its relatively low speeds

• No design standards (rules)

• Needs more defect engineering

• Dissipates heat when written to or read

Conclusion

It is sure that Memristor is going to revolutionaries the 21st century as radically as the transistor in the 20th century But Memristor will have to wait a few years for a killer app like transistor which had to wait almost a decade after it’s invention for the killer app in the form of hearing aids

Finally as Leon O Chua mentioned

It’s time to rewrite all the EE textbooks”

References How We Found the Missing Memristor by Stanley Williams, IEEE

Spectrum December 2008. L.O, Chua, Memristor-missing circuit clement, IEEE Tans . Circuit

Theory, Vol. 18, 1971, pp. 507-519. Memristor and Memristive Systems Symposium, University of California,

Berkeley, November 21,2008. Stateful Implication Logic with Memristors by Eero Lehtonen, Mika Laiho

2009 IEEE/ACM International Symposium on Nanoscale Architectures

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