Without resistors, inductors and capacitors there is no electronic circuit that is worth it. This has been the case for decades, until last May, when HP researchers physically demonstrated what Leon Chua had been theoretically supporting since 1971: the existence of the memristor.
The memristor is, in essence, a resistor with memory. Resistors, one of the most abundant components in any electronic circuit, create a barrier to the passage of electric current, capacitors store a certain amount of electricity and inductors or coils store energy in the form of a magnetic field.
like a flash memory
On the other hand, the memristor is a resistor with memory, a characteristic that can only be reproduced with an impractical and disproportionate combination of a large number of resistors, capacitors, inductors and other elements, something that Chua theoretically tested.
A memristor is like flash memory: it retains data even if the computer is turned off, but it consumes much less power and requires very little material to build.
"The resistance always offers the same level of difficulty to the passage of current; the memristor does not, since it varies depending on the amount of electricity and the direction of flow: in one direction, the resistance increases; in the other, it decreases," explains Leon Chua, who gave a conference at the La Salle Engineering and Architecture School in Barcelona.
The memristor can remember the last voltage it had, so this data can be interpreted in the form of 0s and 1s, but also in a whole gradation of states. In other words, by controlling the electric current that passes through this component, the desired information can be written and deleted.
Chua sees memristors as a good substitute for RAM, which allows the computer to function. The information stored in RAM is temporary, that is, it disappears when the computer is turned off. That's why every time you turn on the computer, the system restarts and you have to wait a long time until the RAM has loaded the operating system data. With a memory built with memristors it would be possible, for example, to leave the Photoshop program in the middle of digital retouching, turn off the computer and, when you turn it on, perhaps weeks later, find everything exactly the same as you left it.
Memristor technology could be applied in the development of computers "that can remember and associate patterns in a way similar to how people do. For example, in facial recognition systems, which would learn based on experience," explains Chua. .
Many processes that require the use of fuzzy logic, such as face recognition, are very difficult to solve using the "yes" or "no" answers, the 0s and 1s of the code of digital computers. "An analog computer based on the functioning of the brain could do it more efficiently."
Digital computers
In the short term, memristors open the door to the construction of instant-on digital computers (with results similar to pressing a light switch), ultra-dense and very economical memories. "The memristor can make flash memories or hard drives obsolete, multiplying storage density and speed by 100 at a cost 100 times lower," says Chua.
In the longer term, the American scientist proposes the creation of analogue operating equipment, which will process information and associate it in a similar way to how the human brain does.