In 1971, Leon Chua predicted the existence of the memristor, short for "memory resistor." This unique component, posited as the fourth passive electronic element alongside the resistor, capacitor, and inductor, regulates electrical current based on its history, retaining a "memory" of past charge flow. Fast-forward to 2008: engineers at HP Labs detected an unusual signal. After a great deal of investigation and debate, they determined that this signal was evidence of the memristor Chua had theorized.
The prediction of the memristor is rooted in the relationships among voltage, charge, current, and flux, which are clearly illustrated in the subsequent diagram.