Flexible and breathable MXene-modified paper-based piezoresistive pressure sensors integrated into airbag pillow for sleep monitoring

Sleeping head monitoring through an intelligent pillow is crucial in warning of disastrous diseases such as suffocation during snoring. However, flexible sensors are still inferior due to limited sensing performance and impermeable wearing discomfort. Herein we develop a flexible pressure sensor by constructing both decorated MXene piezoresistive network and printed interdigital silver electrodes on a dust-free paper platform. The intrinsic paper fabric framework provides good permeability for comfortable skin-attaching, and the microstructured MXene on paper offers good sensing performance with high sensitivity (16.7 kPa-1 < 20 kPa), a wide detection range (~100 kPa), and fast response time (~50 ms). As a proof of concept, the single sensor unit integrated into an airbag pillow for different types of snoring monitoring and five sensor arrays for sleeping head posture recognition by machine learning are both demonstrated. The proposed paper-based sensor, along with the intelligent airbag pillow, provides a promising approach for sleep monitoring in a comfortable unrestricted way.