am2c08434_si_002.mp4 (4.4 MB)
Guar Gum/Ethyl Cellulose-Polyvinyl Pyrrolidone Composite-Based Quartz Crystal Microbalance Humidity Sensor for Human Respiration Monitoring
mediaposted on 2022-07-04, 23:29 authored by Weiyu Yan, Dongzhi Zhang, Xiaohua Liu, Xiaoya Chen, Chunqing Yang, Zhanjia Kang
In this work, the guar gum (GG) and the electrospinned ethyl cellulose-polyvinyl pyrrolidone (EC-PVP) nanofibers were used as humidity-sensitive materials for fabricating a quartz crystal microbalance (QCM) sensor. Fourier transform infrared spectroscopy, scanning electron microscopy, water contact angle test, and X-ray photoelectron spectra were used to characterize the synthesized GG/EC-PVP composite material, confirming its successful preparation and good hydrophilicity. The humidity sensitivity experiments were performed at room temperature. The GG/EC-PVP-coated QCM sensor has high sensitivity (55.72 Hz/%RH) and low hysteresis (2.8% RH) in a wide relative humidity range (0–97% RH), short response/recovery time (26/2 s), excellent selectivity, good repeatability, and stability. The combined action of hydrophilic groups and porous structure enhances the humidity sensitivity. The GG/EC-PVP sensor can be used to capture and measure typical breathing patterns in different human basic emotions due to its good performance. Furthermore, a lie-detector system was also designed for judging the lying through detecting the emotional breathing pattern of the subjects.
scanning electron microscopyray photoelectron spectraquartz crystal microbalanceporous structure enhanceshuman respiration monitoringemotional breathing pattern0 – 97), excellent selectivitypvp composite materialpolyvinyl pyrrolidone compositeelectrospinned ethyl cellulosehumidity sensitivity experimentscoated qcm sensorpolyvinyl pyrrolidoneethyl cellulosehumidity sensitivityhigh sensitivitysuccessful preparationsensitive materialsroom temperaturerecovery timepvp sensorlow hysteresishydrophilic groupsguar gumgood repeatabilitygood performancegood hydrophilicitydetector systemcombined actionalso designed