Displacement Sensor With Nanometric Resolution Based on Magnetoelectric Effect

Micro-displacement measurement is essential in precision fields, such as precision positioning, micro-vibration control and biological engineering. Conventional sensors have disadvantages of susceptibility to environmental, high cost and difficulty in integration. To address these deficiencies, this paper developed a novel displacement sensor with nanometric resolution based on magnetoelectric effect. Combining equivalent magnetic circuit method and equivalent circuit method for magnetoelectric effect using the nonlinear constitutive parameters, an equivalent circuit model of the proposed sensor is established to analyse and predict the performance of displacement sensor. Then a prototype of sensor based on Terfenol-D/PZT composites is fabricated, and the performance of prototype for dynamic displacement amplitude and static position measurement are tested. The results not only validate the developed equivalent circuit model, but also evidence the potential of magnetoelectric displacement sensor. Especially for dynamic displacement amplitude measurement, the resolution of it is better than 13.27 nm, which is close to or even beyond commercial laser displacement sensor.