Wearable and Flexible Helical Pressure Sensor for Noninvasive Respiratory Monitoring

Respiration, an important vital sign, is regarded as the critical parameter for early illness diagnosis and physiological monitoring, which raises an urgent demand for respiratory sensing technology and received great attention due to its promising applications for human healthcare. Here, an ultrasoft helical triboelectric nanogenerator-based pressure sensor is presented with the features of excellent sensitivity, sensing stability, and waterproofness for noninvasive and continuous respiratory monitoring. Leveraging the helical functional fibers inserted in a rubber tube, the pressure sensor is endowed with an extremely high sensitivity of up to 1.726 V/N, a remarkable response time of 20 ms, and mechanical durability under harsh deformations. Thanks to such merits, the pressure sensor is illustrated to be able to recognize respiratory signals, and a real-time respiratory monitoring system with high accuracy has been successfully built for continuous respiratory information acquisition, including respiratory intensity, rate, and interval. These experimental results indicate that the proposed pressure sensor enables the noninvasive and effective monitoring of respiratory behaviors for further assessment and diagnosis of related lung/respiratory disease, suggesting great potential in flexible sensors or wearable electronics for human health care.