The magnetic switching behavior and voltage‐generating characteristics of microduplex‐structured, plastically twisted ferritic Fe‐6∼12% Ni alloys have been investigated. Relatively large voltage pulses (and large currents due to the low resistance of the short magnetic wires) are obtained from properly processed wires, e.g., 0.1–1 V from the ends ∼0.025‐cm diameter and 2–10‐cm‐long wires switched by external ac fields (60 Hz–100 kHz) of 40–200 Oe. It is shown that the residual stress in the plastically twisted wire may not be needed and may even be undesirable since a similarly large voltage is obtained in a sample that has been stress‐relief annealed after plastic twist. Various other factors that affect the voltage generation are discussed. This type of magnetic sensor is free of pickup coils and may conveniently be used as proximity/displacement/rotation sensors or triggering/switching devices. The possibility of biomedical applications as remotely controllable, implanted electrodes for stimulation of nerves or muscles will also be discussed.
展开▼
