Flexible Inductance Pressure Sensor for Wearable Electronic Devices

Abstract

Currently, wearable devices have higher requirements for flexible sensors based on environmental adaptability. Therefore, in order to solve the problem of low sensitivity of current flexible sensors, a new type of flexible inductance pressure sensor is proposed by introducing a ferrite film with high permeability into traditional flexible sensors. The validity and practicability of this method are verified by the research. The results show that the correlation curve of theoretical prediction shows the same trend as the actual curve. Sensor A showed the highest sensitivity of 1.61 kPa−1; Under different bending conditions, the sensitivity difference is 0 ∼ 0.20. When the actual external pressure is increased from 0 to 13.6 Pa, the actual change of inductance is about 0.88%. When the excitation voltage is 0.5 V, the actual inductance output value of sensor A increases from the initial 13.22 μH to 13.26 μH, and the actual change rate is less than 0.30%. In the application of wearable devices, the keys of wearable electronic keyboard have the maximum output voltage variation value, which is greater than 0.15 V, improving the high stability and practicality of the sensor. It is also practical in wearable human respiratory signal detection equipment. In summary, the flexible inductance pressure sensor designed in this study has high performance and practicability in the application of wearable electronic devices, which is of great significance to the development of actual wearable electronic devices.