Airflow-Induced Flexoelectric Bending Sensors for Human Breath Detection

Continuous monitoring of human breathing signals is critical to managing personal health care by early detection of health disorders. Wearable and self-powered devices are attracting growing attention as they show great potential for real-time recording of physiological conditions. Conventional breath monitoring is generally recorded through optical fiber sensing, thermal or camera imaging, which is not portable and difficult to achieve continuous monitoring. Herein, an airflow-induced bending sensor based on flexoelectric effect is developed in this study innovatively. The sensor is prepared through a simple electrospinning process using the low-cost PVDF and Mn3O4. The response time of the bending sensor is only 45 ms, which has obvious advantages over the existing breathing sensors. The breathing sensor prepared in this study can accurately identify different breathing patterns, such as normal, after exercise and coughing. This work paves a way for developing airflow-induced flexoelectric bending sensors with the advantages of fast response, low price, small size, and easy to wear, showing potential applications including bending sensing and health monitoring.