▎ 摘　　要

A quartz surface acoustic wave (SAW) delay line humidity sensor based on three-dimensional architecture graphene (3DAG)/polyvinyl alcohol (PVA)/SiO2 layered sensing film have been proposed and applied in respiration monitoring. An amorphous SiO2 nanolayer was deposited on the total surface of the SAW delay line by radio frequency magnetron sputtering method as a protect coating and sensing film. Then, 3DAG grown on Ta substrate using CVD method was in-situ transformed to the delay area of the SAW device using PVA film to construct a humidity sensor. The prepared humidity sensor exhibits high sensitivity especially under high relative humidity range of 55 %-90 % due to the synergetic effects of the viscoelastic effect of the PVA film, the large absorption and transportation effect of 3DAG, and the mass loading effect of the SiO2. The humidity sensor also has short response and recovery times, good stability, repeatability, and selectivity. Furthermore, the developed humidity sensor was used for respiration monitoring and exhibit excellent capability of monitoring different respiration rates and depths. The respiration variations before and after water drinking can also be recognized by the sensor.