This device is a three terminal memory resistor or memristor. Two terminals are used to drive a current through an electrically conductive wire. The conductive wire is partially covered by an electronically insulating layer which simultaneously acts as a good ionic conductor. The insulating layer is then covered with a gate electrode layer which provides the third terminal of the device. With a voltage applied to the gate electrode, ionic species in the insulating layer can then be pumped to or away from the conductive wire, resulting in modifications of the interface and even of the bulk composition of the conductive wire. The conductive wire and insulator material are chosen such that these modifications in the interface and bulk chemistry result in significant modifications in the resistance of the wire. So in this device, it is not the resistance change in the oxide, but rather the resistance change in the conducting wire that gives rise to memristive switching.