Memristors

MEMRISTORS

Submitted By:Vipul Pandey1102732062

The 4th Basic circuit element.

Overview:IntroductionHistoryWorking PrincipleTypes and ConstructionFuture uses and applicationsConclusion

INTRODUCTION:Made from concatenation of word

MEMory + ResISTOR.Relates electrical charge and magnetic flux linkage. Its current resistance depends on how much electric charge has flowed in what direction through it in the past. These devices are intended for applications in nanoelectronic memories, computer logic and neuromorphic computer architectures.

Vipul Pandey

describing the use of very-large-scale integration (VLSI) systems containing electronic analog circuits to mimic neuro-biological architectures present in the nervous system.

Vipul Pandey

Nanoelectronics refer to the use of nanotechnology in electronic components. Some of these candidates include: hybrid molecular/semiconductor electronics, one-dimensional nanotubes/nanowires, or advanced molecular electronics.

FIGURE:Analogy between Capacitor, Inductor, Resistor and a Memristor.

HISTORY:1808Sir Humphry Davy is claimed by Leon Chua to have performed the first experiments showing the effects of a memristor.1960Bernard Widrow coins the term memistor (i.e. memory resistor) to describe components of an early artificial neural network called ADALINE.

2012On March 23 HRL Laboratories and the University of Michigan announced the first functioning memristor array built on a CMOS chip for applications in neuromorphic computer architectures.

2013On February 27 Thomas et al., constructed a memristor capable of learning. The approach utilizes memristors as key components in a blueprint for an artificial brain.

DeviceCharacteristic property

(units) Differential equation

ResistorResistance (V per A, or Ohm, Ω) R = dV / dI

CapacitorCapacitance (C per V, or Farads) C = dq / dV

InductorInductance (Wb per A, or Henrys) L = dΦm / dI

MemristorMemristance (Wb per C, or Ohm) M = dΦm / dq

Working Principle:

The memristor was originally defined in terms of a non-linear functional relationship between magnetic flux linkage Φm(t) and the

amount of electric charge that has flowed, q(t):

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

Types1. Molecular and Ionic Thin Film Memristive Systems• Titanium dioxide memristors.• Polymeric (Ionic) memristors.• Manganite memristive systems.• Resonant-Tunneling diode memristors.• Silicon oxide memristors.

2. Spin Based and Magnetic memristive systems• Spintronic memristors.• Spin torque transfer (STT) MRAM

Vipul Pandey

In general, though, for any material, Hysterisis, an accelerating rate of change of a property as objects move from one state to another, is an indicator of memristive properties.

Molecular and Ionic Thin Film Memristive Systems

These type of memristors primarily rely on different material properties of thin film atomic lattices that exhibit hysteresis

under the application of charge.

Vipul Pandey

Hysteresis is the dependence of a system not only on its current environment but also on its past environment. This dependence arises because the system can be in more than one internal state.

Titanium dioxide memristor

• Composed of a Titanium Dioxide film between two 5 nm thick electrodes.

• Titanium dioxide changes its resistance in the presence of oxygen, which is why its used in oxygen sensors.

• To access the memristive properties, crossbars of nanowires are placed above and below the top and bottom layers, so that a charge can be passed through.

Vipul Pandey

Currently Hewlett Packard’s version of the Titanium Dioxide susbtrate memristor is the most generally pursued type of memristor.

Spin Based and Magnetic memristive systems

Spin-based memristive systems, as opposed to molecular and ionic nanostructure based systems, rely on the property of

degree of freedom in electron spin.

Vipul Pandey

A type of magnetic memristor under development by several labs, notably Seagate

Spintronic Memristor

• Resistance is caused by the spins of the electrons.• Electrons flowing into the device have a certain spin,

which alters the magnetization state of the device.

Spin Torque Transfer Magnetoresistance

• The resistance here is dependent on the relative spin orientation between two sides of a magnetic tunnel junction.

• This in turn is controlled by the spin torque induced by the current flowing through the junction.

Vipul Pandey

Spintronics, also known as spinelectronics or fluxtronic, is an emerging technology exploiting both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, in solid-state devices.

Vipul Pandey

Spin Torque Transfer Magnetoresistance is a well-known device that exhibits memristive behavior. The resistance is dependent on the relative spin orientation between two sides of a magnetic tunnel junction. This in turn can be controlled by the spin torque induced by the current flowing through the junction. However, the length of time the current flows through the junction determines the amount of current needed, i.e., the charge flowing through is the key variable.

ADVANTAGES

Memristors do not have the limitations of resistors.

1. Memory resistors do not have the theoretical heat limitations.

2. Memory resistors are smaller and can be stacked for increased capacity per cubic space.

3. They use less energy, and they can be used for processing and memory storage.

4. Even better, memory resistors are faster, and can store more data.

5. Best of all they retain that memory; they do not have a boot-up delay.

ApplicationsAnd

FUTURE SCOPE

Used as RRAM

• Resistive random-access memory (RRAM) is a new non-volatile memory type which promises to replace the existing flash memory

• Resistive switching memories are based on materials whose resistivity can be electrically switched between high and low conductive states. RRAM has superior intrinsic scaling characteristics compared to the charge-based Flash devices, and potentially small cell size.

• Non-Volatile memory.• Booting free computer.• Artificial Intelligence.• Memristor patents include applications

in programmable logic, signal processing, neural networks, control systems, reconfigurable computing, brain-computer interfaces.

Extensive research is being done over the memristor technology.

It is sure that Memristor is going to revolutionaries the 21st century as radically as

the transistor in the 20th century.

CONCLUSION

REFERENCES• www.memristors.org• Wikipedia• Outsideinnovation.blogs.com• Eweek.com• Techradar.com• Prnewswire.com• http://technorati.com/technology/embedded/article/memristors-technology-

breakthrough/

• http://spectrum.ieee.org/semiconductors/devices/spintronic-memristors• http://

egodwin2.blogspot.in/2009/10/memristors-advantages-and-disadvantages.html

http://www.memristors.org/

http://technorati.com/technology/embedded/article/memristors-technology-breakthrough/



http://spectrum.ieee.org/semiconductors/devices/spintronic-memristors

http://spectrum.ieee.org/semiconductors/devices/spintronic-memristors

http://egodwin2.blogspot.in/2009/10/memristors-advantages-and-disadvantages.html



THANK YOU !

Education

Memristors