MEMRSITOR

MEMRISTORPresented by: LOKESH RInternal guide: JULIA SAM (Asst prof MVJCE)OverviewIntroductionFeaturesPhysical analogy of MemristorConstruction and workingAdvantage &Applicationsconclusion

IntroductionKnown 3 fundamental passive circuit elements: Resistor, Inductor& Capacitor

In 1971,Leon Chua, a professor of electrical engineering at the university of California predicted the existence of the fourth fundamental device. "THE MEMRISTORHe proved that memristor behavior cannot be duplicated by any circuit built by other three fundamental devices", which is why memrsitor is truly a fundamental component.Memristor is a contraction of memory resistor, because that is exactly its function-To remember its history.Leon Chua gave pair wise mathematical equations that relate the four circuit quantities.

Feature of MemristorA memristor is a two terminal semiconductor device whose resistance depends on the magnitude and polarity of the voltage applied to it and the length of time that voltage has been applied When the voltage is turned off, the memristor remembers its most recent resistance until the next time you turn it on.As its name implies, the memristor can remember how much current has passed through it. This make memristor a unique device. UNIT=Ohms()

Physical analogy for memristorResistor is analogous to a pipe of fixed diameter through which water flowsWater(charge q), input pressure(voltage v), rate of flow of water(current i).Resistance depends on diameterMemristor is analogous to special kind of pipe that expands or shrinks when water flows through it. when water flows in one when water flows in opp direction the diameter direction the diameter increases( resistance decreases) decreases(resistance increases)

Construction and working First solid state version of memristor was built by a research team of HP Labs.Built using Titanium dioxide with cross bar structure.The cross bar is an array of perpendicular platinum wires. Anywhere two wires cross, they are connected by a switch.

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The top and bottom layer are separated by a switching element, TiO2(Titanium dioxide)The layer connected to the bottom platinum wire is initially perfect TiO2 and the other half is an oxygen deficient layer of TiO2 represented by TiO(2-x) X= amount of oxygen deficienciesPlatinum wires are selected to apply power in either of the directionsA positive direction will attempt to open the switch and negative direction will attempt to open the switchContd

As the positive current is applied, the positively charged oxygen vacancies push their way into pure TiO2 causing the resistance in the gap material to drop, becoming more conductive, and current to rise.

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As the negative current is applied, the oxygen vacancies withdraw from the pure TiO2 causing the pure and more resistive TiO2 , becoming less conductive, and slowing the current.

AdvantagesReliability when power is interruptedGreater data densityLess expensiveDoesnt consume power during idleFaster than flash memoryQuicker boot up of computersApplications As a switchAs a non volatile memoryCan perform logic operationsIn artificial neural networksConclusionMemristor technology has the potential to open the door to brand new type of electronics.Memristor will change circuit design in 21st century as radically as the transistor in 20th century.May replace transistors in ICs Memristor qualifies as fundamental circuit element

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