MEMRISTOR A New Bond graph Element

What Is Memristor… ? Memristors are basically a fourth class of electrical circuit, joining the resistor, the capacitor and the inductor that exhibit their unique properties primarily within the nanoscale. Fig. : symbol of memristor This is a combination of ‘Memory and Resistors’.

These are the type of passive circuit elements that maintain a relationship between the time integrals of current and voltage across a two terminal element. 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. Fig. : Memristor

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.

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. Memristor ("memory resistor") is any of various passive two-terminal circuit elements that maintain a functional relationship between the time integrals of current and voltage.

This function is called memristance. Other devices like batteries and varistors have memristance, but it does not normally dominate their behavior. Memristors are nonlinear and may be described by any of a variety of time-varying functions of net charge.

There is no such thing as a generic memristor. The memristor is formally defined as a two-terminal element in which the magnetic flux(Φm) between the terminals is a function of the amount of electric charge(q) that has passed through the device. Each memristor is characterized by its memristance function describing the charge-dependent rate of change of flux with charge.

It can be said that memristance is simply charge-dependent resistance. Memristive behavior is based entirely on the electron-spin degree of freedom, which allows for a more convenient control than the ionic transport in nanostructures.

The most basic mathematical definition of a current-controlled memristor for circuit analysis is the differential form. a memory effect is achieved in solid-state thin film two-terminal devices. Fig. : Me,ristive System

In that case, the memristive behavior is based on the coupling between transport of atomic degrees of freedom. Eample: oxygen vacancies acting as mobile dopants defining the internal state of the device_ and of electrons. The electron current flowing through such a device dynamically changes the internal state of the latter, which, in turn, influences the electron transport in a nonlinear way.

Memristor Types Divided into 4 parts they are depending upon behavior of Memristor. Spintronic Memristor Titanium dioxide Memristor 3-terminal Memristor 2-terminal Memristor1

About Spintronic memristor Nothing but Magneto Memristor This Memristor are developed by researchers yirn chen and wang by using seagate technology Every electron having certain spin in the devices, the spin of electron can be effected by magnetization, which changes the resistance of the device.

Titanium dioxide memristor Nothing but Non-Ionic device This type developed by sir. Williams by using the solid-state technology A thin film Tio2 having a size 50nm which are placed between two electrodes this are 5nm, the material uses for the electrodes is pl or Ti Initially the two layers as Tio2 film, one of which layer is depletion layer other one’s is non- depletion layer

In the depletion layer O2 act as charge carrier When the electric field is applied, O2 is drift and change the boundary layer from high resistance to low resistance The resistance of the layer is dependent on how much charge has passed through in particular direction

3 & 2-Terminal Memristor The Solid state memristor can be combined into a devices which’s formed as 3- terminal memristor which is called as “Cross bar latches” In future transistor replace “Cross bar latches” Advantage – much smaller area 2 Terminal Memristor’s are memcapacitor and meminductors The properties depends on state and history of the system

Potential applications of Memristors Resistive Random Access Memory (RRAM) Memristor as Switch Faster than Flash memory Conventional devices use only 0 and 1; Memristor can use anything between 0 and 1 (0.3, 0.8, 0.5, etc.)

Resistive Random Access Memory (RRAM) The computer have to be rebotted every time they are turn ON The logic circuit of computer is incapable of holding their bits after the power Off by using of memristor it can be over come HP is currently focusing on this possibility HP invests tens of millions of dollars in the analysis of prospects for new technology.

Memristor as Switch The memristor can be used as switch by using of solid-state technology A team of HP conducted a experiment by building a nanoscale memristor switch- 50nm The name of switch implies A chemical is used between the layers such as sunscreen and white paint between

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 by using the memristors.

Limitation As this is an extremely new technology, the only limitation is what you make.

Fourth basic circuit element , It carries a memory of past… Conclusion Fourth basic circuit element , It carries a memory of past…

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