Presented By J.Shabarinath (08BA1A0442)

 It is a type of resistor in which the flow of electrical current in an electronic circuit is determined by the amount of charge that has previously flowed through it.  It is also known as “Memory Resistor.” Electrical Symbol

 Memristors are passive two terminal circuit elements.  Behaves like non linear resistor with memory.  Currently known fundamental passive elements-Resistors,Inductors and Capacitors.  Does a 4 th Passive element exist ?

 In 1971 Leon chua, a professor at UC Berkeley postulated a new circuit element in the article “Memristor the missing circuit element.”  In 2008 a tem at HP labs announced the development of a switching memristor based on a thin film of titanium dioxide.  By 2013 the first product using memristor technology are expected to become available.

 Four fundamental circuit variables-current i, voltage v, charge q and flux linkage φ.

 Memristance is a property of an electronic component.  When charge flows in one direction, its resistance increases, and if direction is reversed, resistance decreases.  When v=0, charge flow stops & component will ‘remember’ the last resistance it had.  When the flow of charge regains, the resistance of the circuit will be the value when it was last active.

 Resistor is analogous to a pipe that carries water.  Water(charge q), input pressure(voltage v), rate of flow of water(current i).  In case of resistor, flow of water is faster if pipe is shorter and/or has a larger diameter.

 Memristor is analogous to a special kind of pipe that expands or shrinks when water flows through it  The pipe is directive in nature.  If water pressure is turned off, pipe will retain its most recent diameter, until water is turned back on.

 On April 30, 2008, a team at HP Labs led by the scientist R. Stanley Williams announced the discovery of a switching memristor.  It achieves a resistance dependent on the history of current using a chemical mechanism.  The HP device is composed of a thin (5nm) Titanium dioxide film between two Pt electrodes.

 Initially there are two layers, one slightly depleted of Oxygen atoms, other non-depleted layer.  The depleted layer has much lower resistance than the non-depleted layer.

Al,TiO sandwidched

An atomic force microscope image of a simple circuit with 17 memristors lined up in a row. Each memristor has a bottom wire that contacts one side of the device and a top wire that contacts the opposite side. The devices act as 'memory resistors', with the resistance of each device depending on the amount of charge that has moved through each one. The wires in this image are 50 nm wide, or about 150 atoms in total width.

 Provides greater resiliency and reliability when power is interrupted in data centers.  Have great data density.  Combines the jobs of working memory and hard drives into one tiny device.  Faster and less expensive than RAM.

 Uses less energy and produces less heat.  Would allow for a quicker boot up since information is not lost when the device is turned off.  Creating a Computer that never has to boot up.

Could be put in cell phones as monitoring devices to track pollution and other things in the environment.  Used in common devices for unbelievable storage.  Camera can take days worth of video with storage the size of an average thumb drive.

 For the development in robotic as well as robonaut technology.  In RRAM ( resistive random access memory )  We can widely use in self programming circuits.  In large storage applications.

 In large storage RAMS and Hard Disks

 In communication

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