A memristor is an electrinic compinent where the resistance varies depending on its history of past electrical crrent flows. Quantum dot versions have been suggested as a possible technology for reservoir computing. American Scientist explained a memristor using the analogy of a sand and gravel filter in a water system that gradually clogs with sediment and so needs to be perioidcally cleaned by a flow in the opposite direction.
Used in Chap. 7: page 99
Links:
americanscientist.org: American Scientist : The Memristor