Smart filtering facepiece respirator with self-adaptive fit and wireless humidity monitoring.

The widespread emergence of airborne diseases has transformed our lifestyle, and respirators have become an essential part of daily life. Nevertheless, finding respirators that fit well can be challenging due to the variety of human facial sizes and shapes, potentially compromising protection. In addition, the current respirators do not inform the user of the air quality in case of continuous long-term use. Here, we introduce a smart filtering facepiece respirator incorporating a humidity sensor and pressure sensory feedback for self-fit adjusting and maintaining an adequate fit. The humidity detection sensor uses laser-induced graphene, and the pressure sensor array based on the dielectric elastomeric sponge monitors the respirator contact on the user's face, providing real-time closed-loop feedback and the wearer's fitting status. Those membrane sensors show outstanding performance, such as a low humidity hysteresis of 0.131 % and a precise pressure detection limit of 0.23 ± 0.02 kPa. As a result of the self-fit adjusting mode, the overall fit factor is increased by 10 % on average compared to the commercial respirator. This significant improvement in fit factor, coupled with the innovative design, has the potential to develop next-generation facepiece respirators as essential personal protective equipment.