Study On Force Sensitive Properties And Its Sensor Of FeSiBY Amorphous Alloy Film

Flexible force-sensitive film sensors are widely used in wearable devices,electronic skin,human-computer interaction and other fields due to their advantages of simple manufacturing process,low cost,strong flexibility and great integration potential.Piezomagnetic type force-sensitive film sensor is a hotspot of current sensor research.For piezomagnetic flexible force-sensitive film sensor,the magnetic film as a sensitive element is the key to achieve high sensing performance.Iron-based amorphous alloy films have excellent piezomagnetic properties and piezomagnetic stability,and have broad application prospects in the development of piezomagnetic sensors.In this paper,FeSiB amorphous alloy flexible force-sensitive film was studied,a flexible force-sensitive composite film with double-layer structure was designed and fabricated.The force-sensitive mechanism and the piezomagnetic properties of force-sensitive film under different conditions was investigated.The composite film has a complex force-sensitive mechanism,which corrects the fluctuation of the force-sensitive curve and improves the force-sensitive stability at the initial stage.Compared with the single FeSiB amorphous alloy film,the sensitivity of the composite film significantly improved.When the thickness of the composite film is180 μm～270 μm,the film has excellent force-sensitive properties in the 0～0.1 MPa compressive stress range.When the thickness of the composite film is 200μm and the test frequency is 1 KHz,the sensitivity of the composite film is 0.27 μH/KPa,and the force-sensitive curve in the sensitive range changes approximately linearly.When the thickness of the composite film is 230 μm and the test frequency is 1 KHz,the sensitivity is 0.59 μH/KPa,the force-sensitive curve in the sensitive range is an approximate linear change.The composition of FeSiB amorphous alloy film was modified by rare earth element Y,which was used to regulate the saturation magnetostriction coefficient of the film and modulate the piezomagnetic effect of FeSiB amorphous alloy film.The monolayer FeSiBY film showed linear variation in the microstress interval from 0 to1.2 KPa with a sensitivity of 88.87 μH/KPa,which was much better than that of FeSiB amorphous alloy film(0.2 μH/KPa).The linear range of the piezomagnetic effect of the sensor was broadened by the superposition of FeSiBY film,and the upper limit of the linear range of the piezomagnetic curve of the sensor after superposition by four layers of film reached 16 KPa,and the sensitivity still reached6.84 μH/KPa.Using the investigated piezomagnetic FeSiBY flexible force-sensitive film sensor,the application of this type of sensor for subtle finger pressure,pulse,air motion and vocal cord detection was successfully demonstrated,highlighting its potential for real-time monitoring and providing options for the development of new flexible force-sensitive film sensor that is highly sensitive,stable and suitable for batch manufacturing.