The fourth passive electronic circuit element, the memristor, has been build by HP labs. Like before the resistor, capacitor, inductor, it links two properties of electricity, in this case the magnetic flux and the electric charge that has passed through the device. In other words, the memristor is a charge-dependant resistor.
Memristance is a property of an electronic component. If charge flows in one direction through a circuit, the resistance of that component of the circuit will increase, and if charge flows in the opposite direction in the circuit, the resistance will decrease. If the flow of charge is stopped by turning off the applied voltage, the component will ‘remember’ the last resistance that it had, and when the flow of charge starts again the resistance of the circuit will be what it was when it was last active.
Although Leon Chua first proposed their existence in 1971, only now they could be build, because memristance effects come into play strongly at nano scales.
To the left is an image of a circuit with 17 memristors made from titanium dioxide, the wires are 50 nm – about 150 atoms – wide.
From what I gather, this technology will have a profound impact, where it will not only be possible to calculate something only using 0 and 1 (binary), but also using values between 0 and 1. Sounds like perfect hardware for fuzzy logic.