A memristor is passive two-terminal circuit elements that maintains a functional relationship between the time integrals of current and voltage. Memristors are basically a fourth class of electrical circuit, joining the resistor, the capacitor, and the inductor, that exhibit their unique properties primarily at the nanoscale. It describes the variation in Resistance of a component with the flow of charge.
Thus, a memristors resistance varies according to a devices memristance function, allowing, via tiny read charges, access to a applied voltage.Memristors are nanoscale devices with a variable resistance and the ability to remember their resistance when power is off
The material implementation of memristive effects can be determined in part by the presence of hysteresis (an accelerating rate of change as an object moves from one state to another)
However, on April 30, 2008, a team at HP Labs led by the scientist R. Stanley Williams announced the discovery of a switching memristor. Based on a thin film of titanium dioxide, it has been presented as an approximately ideal device.
The known three fundamental circuit elements as resistor, capacitor and inductor relates four fundamental circuit variables as electric current, voltage, charge and magnetic flux. In that we were missing one to relate charge to magnetic flux. That is where the need for the fourth fundamental element comes in. This element has been named as memristor.
HOW HP fabricates the Memristors?
HP fabricates them using conventional lithography techniques: laying down a series of parallel metal nanowires, coating the wires with a layer of titanium dioxide a few nanometers thick, and then laying down a second array of wires perpendicular to the first. The points where the wires cross are the memristors, and each can be as small as about three nanometers. This cross-bar structure also makes it possible to pack memristors in very dense arrays.
Advantages of Memristors
1)Provides greater resiliency and reliability when power is interrupted in data centers.
2)Combines the jobs of working memory and hard drives into one tiny device.
3)Faster and less expensive than MRAM.
4)Have great data density.
5)Uses less energy and produces less heat.
6)Would allow for a quicker boot up since information is not lost when the device is turned off
7)Operating outside of 0s and 1s allows it to imitate brain functions.
8)A soft and slow current causes it to act as an analog device.
9)A fast and hard current causes it to act as a digital device.
1)Low-power and remote sensing applications
2)Non-volatile memory applications
3)Crossbar Latches as Transistor Replacements or Augmentors
4)Circuits which mimic Neuromorphic and biological systems (Learning Circuits)
5)Programmable Logic and Signal Processing