All Inkjet-Printed B Field Sensor

Abstract

This paper presents the realization and the experimental characterization of a low cost inkjet-printed DC magnetic field sensor. The device consists of a thin flexible cantilever beam operated at its first resonance frequency by the interaction between the target magnetic field and an AC current flowing through a coil printed on the beam. A resistive readout strategy is implemented by a printed strain gauge to measure the beam deflection strength, which is correlated to the target field strength. A dedicated electronics is used for the sake of the sensor operation. The sensor behaviour has been investigated for different values of the driving current and the target magnetic field. As an example, the sensor responsivity and resolution for a driving current of 20 mA @ 9.1 Hz (the beam resonance frequency) are 0.009 Ω/Ω/T and 1.2 mT, respectively.