A new piezomagnetic film force sensor model for static and dynamic stress measurements

Highlights: • The development of a novel piezomagnetic force sensor with a closed inductance loop. • Introducing annular yoke outside the inductance coil to improve the sensor anti-interference ability. • With controlling the internal stress state, the sensor can be used in dynamic and static stress tests. In this study, an Fe_73.5Cu₁Nb₃Si_13.5B₉ amorphous alloy film was used as a sensing chip for the development of a novel piezomagnetic force sensor model with a closed inductance loop. The sensor exhibits an excellent anti-interference ability against the electromagnetic effects from the environment. Reliable data is obtained at temperatures smaller than 60 °C. Furthermore, the piezomagnetic properties of the Fe_73.5Cu₁Nb₃Si_13.5B₉ films annealed at different conditions were investigated. After annealing at 350–555 °C, the elastic hysteresis of the sensing chip was weakened, which is beneficial in dynamic stress measurements. The optimal stress range for static and dynamic measurements is 0–2 kPa, where the sensitivity is 3.5 μH/kPa. When the annealing temperature is 150 °C, the piezomagnetic effect of the film is significant and elastic hysteresis is obvious, which is suitable only for static stress measurements. In the range 0–10 kPa, the force-sensitivity performance curve is linear with a sensitivity of 3 μH/kPa, which demonstrates its excellent force-sensitivity properties.