Self‐Powered Rapid Response Flexible Pressure Sensor for Wearable Application

Flexible pressure sensors have attracted a lot of attention in fields such as medicine and healthcare due to their ease of making wearable devices. However, the development of flexible pressure sensors is facing the challenges of a complex manufacturing process and high cost. Herein, a zinc oxide (ZnO) piezoelectric film flexible pressure sensor with a 3 × 3 sensor array presented through an extremely simple and ultralow‐cost fabrication process is reported. The 3 × 3 sensor array in series and again, in parallel. The output voltage of the 3 × 3 sensor array is significantly higher compared to the original thin‐film piezoelectric sensors at the same film thickness. The ZnO flexible pressure sensor shows good linear sensitivity and high durability over 4000 cycles of loading in the test range of 0–14 N. The response and recovery times tend to decrease as the dynamic pressure increases in the experimental range. Furthermore, a high‐precision dynamic force calibration system through a comparison between the open‐loop and closed‐loop strategies used in the dynamic force calibration experiments that are performed is presented. Potential applications of the sensor are demonstrated, including elbow flexure and finger tapping. The sensor also shows the ease of massive fabrication.