A memristor ( a memory resistance portmanteau) is a non-linear, two-passive nonlinear electrical component that relates the electric charge and the coupling of the magnetic flux. It was conceived, and its name coined, in 1971 by the theorist of the circuit Leon Chua. According to the mathematical relations that characterize it, the memristor would hypothetically operate as follows: The electric resistance of the memristor is not constant but depends on the current history that previously flowed through the device, ie its current resistance depends on how much electric charge has flowed in which direction through it in the past; the device remembers its history - the property called non-volatility. When the power supply is off, the memristor remembers its most recent resistance until it is turned back on.
In 2008, an HP Labs team claimed to have found the missing Chrystal memristor based on an analysis of a thin titanium dioxide film, thus connecting the operation of RRAM devices to the memristor concept. The result of HP was published in the journal Nature. Following this assertion, Leon Chua has argued that the definition of the memristor could be generalized to encompass all forms of non-volatile memory devices of two terminals based on resistance switching effects. However, there are serious doubts about whether the memristor can actually exist in physical reality. In addition, some experimental tests contradict the generalization of Chua, since a non-passive nanobattery effect is observable in the resistance switching memory. Chua also argued that the memristor is the oldest known circuit element, with its predecessor effects, capacitor and inductor.
These devices are intended for applications in nano-electronic memories, computational logic and neuromorphic / neuromemocratic architectures. In 2013, Hewlett-Packard's Martin Fink CTO suggested that commercial availability of memristor memory could arrive as early as 2018. In March 2012, a team of researchers from HRL Laboratories and the University of Michigan announced the first memristor array running on a CMOS chip.