A memristor, short for “memory resistor,” is a type of passive two-terminal electronic component that exhibits a relationship between the electrical charge that has flowed through it in the past and the current that flows through it in the future. The fundamental principle of a memristor is based on its ability to change resistance in response to the amount of electric charge that passes through it over time. Unlike resistors, which obey Ohm’s law and have a fixed resistance, memristors have a resistance that can be “memorized” or changed based on the history of the electrical signals applied to them.
An intuitive explanation of a memristor can be likened to a resistor that remembers how much current has passed through it. When current flows through a memristor, it alters its resistance. If the current stops flowing, the memristor retains its last resistance state until another current passes through it and changes it again. This behavior allows memristors to store and recall information about the quantity and direction of charge that has flowed through them, similar to how a resistor stores information about voltage and current.
One example of a memristor structure involves thin films of titanium dioxide sandwiched between two electrodes. The movement of oxygen vacancies within the titanium dioxide film alters its resistance in response to electrical pulses, thereby demonstrating the memristive effect. This structure allows memristors to operate efficiently with low power consumption and can potentially revolutionize computing and memory storage technologies by offering non-volatile memory and neuromorphic computing capabilities.
The relationship established by a memristor is between the amount of charge that has passed through it (Q) and the resulting change in resistance (ΔR). This unique property makes memristors valuable in applications requiring analog memory storage, synaptic emulation in artificial neural networks, and energy-efficient computing. The development and understanding of memristors have opened up new possibilities in electronics, offering potential advantages in terms of speed, power consumption, and integration compared to traditional computing and memory technologies.