Fast-response humidity sensor based on laser printing for respiration monitoring.

Respiration monitoring equipment has wide applications in daily health monitoring and modern medical diagnosis. Despite significant progress being made in humidity sensors for respiration monitoring, the fabrication of the humidity sensors with low-cost, simple manufacturing process and easy integration remains a challenge. This work reports a facile and inexpensive laser printing fabrication of PEDOT:PSS micron line as a humidity sensor for respiration monitoring. Laser printing technology can process any material into an arbitrary pattern. The PEDOT:PSS micron line humidity sensor has a fast response-recovery time (0.86 s/0.59 s), demonstrating excellent performance for real-time monitoring of human respiration. Furthermore, the PEDOT:PSS micron line humidity sensor can also monitor the respiration of rats under different physiological conditions along with the drug injection. The PEDOT:PSS micron line humidity sensor features simple manufacturing process with commercial materials, and easy integration with wearable devices. This work paves an important step in real-time monitoring of human health and further physiology and pharmacology study.