AC & DC Magnetic Field Sensor Based on Flexible Piezoelectric Polymer

Using flexible polymer to make passive magnetic field sensor is a feasible way. Flexible piezoelectric polymer combined with permanent magnets were used to build a cantilever beam structure to measure AC and DC magnetic fields. In magnetic field, the piezoelectric material vibrates in different modes under the drive of a permanent magnet. The magnetic field measurement mechanism was studied and a finite element simulation model of the piezoelectric cantilever beam was built. The sensor successfully detected AC magnetic field (sine-wave, 50Hz, 0–20 Oe) and DC magnetic field (0–50 Oe). Under the AC and DC magnetic field, the voltage outputs with the sensitivity of the sensor are 0–22 V with 1.1V/Oe and 0–1 V with 20 mV/Oe, respectively. Compared with existing technologies, this paper provides a room-temperature sensor that measures both AC and DC magnet field through a simple and low-costed way.