Dome structure nonwoven-based dual-mode pressure-humidity sensor: Enhancing sensitivity and breathability for human health monitoring

In the field of health monitoring and electronic skin, flexible wearable sensors have attracted considerable research interest. However, preparing a flexible multifunctional sensor that simultaneously possesses a rapid response time, stability, reliability, high breathability, as well as high sensitivity remains a significant challenge. Herein, a flexible pressure-humidity dual-mode sensor based on nonwoven fabrics is developed in this study, using hydroentangled nonwoven fabric with graphene oxide/carbon nanotube composite as the sensing layer and polyester plain nonwoven fabric with carbon nanotube printed interdigitated electrodes as the electrode layer. The sensor exhibits high permeability (649.2 mm/s), high sensitivity (2.72 kPa⁻¹), wide sensing range (0–220 kPa), fast response/recovery time (24.4 /73.3 ms), and low detection limit (2.79 Pa). In addition, the sensor exhibits excellent cyclic stability (15,000 cycles) and can detect both weak body movements (pulses, swallowing) as well as large deformational movements (joint movements). Furthermore, the sensing layer of the sensor responds quickly to different humidity levels, which can be used to monitor humidity in real time, and human breathing and speech can be monitored by placing it inside a mask. This high-performance flexible pressure-humidity dual-mode sensor shows promising potential for applications in health monitoring and respiratory monitoring.