A memristor circuit is a passive component in which the resistance changes in relation to the charge that passes through the device and which can remember the last charge that passed through it even when the charge is removed. Circuits are made of three primary passive components: capacitors, resistors, and inductors. The discovery of the memristor adds a fourth component to circuitry which can lead to advances in computer technology and nanotechnology. The smaller a memristor circuit is, the better it functions. This allows scientists to create smaller and smaller circuit boards.
Leon Chua first theorized the possibility of the memristor circuit in 1971 while working at the University of California in Berkeley. The actual invention of the memristor did not occur until 2008 when HP Labs finally created a working version from a thin strip of titanium dioxide which had been doped, or altered, to include fewer oxygen atoms then it should. When a charge runs in one direction through the memristor, it gives it a higher resistance. When the charge passes through in the opposite direction, the resistance lowers.
The combination of the memristor circuit's small size and ability to remember the last charge that passed through it unlocks many doors in the world of electronic circuitry. Circuit boards must be a certain size to fit all the transistors and other pieces on them. With the discovery of memristors, these components can shrink to a fraction of their current size.
Ability to remember what charge last passed through makes the memristor even more astonishing. When a user turns off a computer, it loses any unsaved data because power is required for the computer to "remember" the data. Memristors, however, remember this data even without power, so the user could turn the computer off and on to find it exactly how he left it when he turned it off.
Not only would the use of memristor circuits create smaller circuit boards, larger memory, and the ability to store memory even with the power is gone, the quality of a memristor circuit that allows it to change its resistance in relation to the charge passing through means in the future scientists may be able to create computers which can "think." Currently, a circuit is either off or on depending on whether a charge is flowing through it. If, however, memristor circuits were used then the computer could cover a range of values between off and on and thus make more complex decisions.