Right now we have resistors, capacitors, and incutors we also have four basic circuit variables current, voltage, charge and flux. I am not an engineer but my understanding is, that with these variables you should be able to have four different components and not just three. The fourth component known as a memristor was first theorized in 1971 by Leon Chua. This theoretical fouth component would have properties that were not reproducable by the other three components alone or in any combination.
The memristor is indeed different from its brothers. When a charge is passed through the circuit in one direction its resistance increases, when it is passed through the other direction it decreases. This amount of resistance is analog as well. This means a memristor can store values that don’t just equate to one or zero although their first use will probably be to make solid state memory that is faster than any memory that already exists and has a data density greater than a factor of ten from todays solid state memory like flash memory. It is much less volatile than flash memory as well so it will last longer, and the state of the memristor can be read using similar techniques to todays memory cirtuits so it it doesn’t require any fundamental changes to underlying hardware.
Since memristors can store large amounts of data in such a small area they are perfect for memory components in nanoscale machines, the ultimate new automata of the future. They can also double as processor components that are dynamically changed as needed. So not only can the memristor function as a memory it can be made to function as a processor as well.
Memristors due to their analog nature function very similarly to human neural networks. The memristor can retain data from reinforcement learning very easily, a few hundred memristors can simulate a full human neuron in a similar amount of space.
Memristors are truly an amazing breakthrough and could lead to a paradigm shift in toadys technology.