研究背景

呼吸疾病如COVID - 19、甲型流感、病毒性流感和哮喘等持續(xù)對人們的生活構成挑戰(zhàn)，是必須解決的重要健康問題。可穿戴濕度傳感器可監(jiān)測呼吸狀態(tài)和體表濕度，濕度作為一種生理信號，在反映人體健康狀況方面起著至關重要的作用。柔性濕度傳感器作為一種可以感知外部濕度變化的設備，可以測量因濕度變化產生的物理變化，并將其轉化為電信號或其他方便檢測的信號。其對外部濕度的檢測依靠敏感材料完成，比如高分子聚合物、金屬氧化物等等。其中某些新型納米材料被廣泛應用于傳感器制造中。目前制備方法簡單且具有高靈敏度稱為決定柔性濕度傳感器能否被廣泛應用的重要因素，因此開發(fā)具有高靈敏度、制備簡單的柔性濕度傳感器具有重要意義。

研究成果

魯東大學陳雪葉團隊在期刊《Journal of Materials Chemistry A 》，發(fā)表名為“Non-contact porous composite fiber paper-based humidity sensor forwearable breathing and skin humidity monitoring”的論文。研究者利用簡單的制造工藝制備出具有快速響應功能的柔性紙基濕度傳感器，利用CO2激光器制備出插指電極結構，并同時利用復合紙纖維等納米復合材料制備了具有多孔纖維結構的柔性濕度傳感器。該制備方法不受任何條件限制，具有廣泛的適用性。

圖文導讀

Fig. 1 (a) Overall structure, (b) internal structure, (c) non-contact humidity response process, (d) experimental environment, and (e) reaction mechanism.

Fig. 2 (a) Preparation flow, (b) XRD patterns, (c) ultra-depth-of-field microscope images of the surface of paper and electrodes, (d) PLFC object and electrolytic oxidation of the metal electrode in air, (e) SEM of the moisture-sensitive paper, (f) SEM of the paper fiber pore electrode.

Fig. 3 Performance test of PLFC: (a) linear fit of humidity, (b) six cycles at 12% and 43% humidity, (c) corresponding amplitude of different humidity gases, (d) corresponding amplitude of moistened paper to different humidity gases,(e)electrolytic lithium chloride solution,(f) response of PLFC, (g) PLFC made of 10% concentration of lithium chloride in a 75% humidity environment, (h) humidity response of PLFC when there is a certain amount of moisture, (i) air and 75% RH gas and 43% RH gas at the time of PLFC contact.

Fig. 4 PLFC respiratory monitoring: (a) schematic diagram of respiratory monitoring, (b) Cheyne–Stokes breath, (c) breathing and pause breathing simulation perceptual performance, (d) normal breathing after coughing, (e) breathing through the nose and mouth, and huffing respectively, (f) saying “hello” in different languages, (g) rapid breathing, and (h) deep breathing.

Fig. 5 Application of PLFC in human skin humidity monitoring: (a) PLFC application scenarios and schematic diagram, (b) humidity response of various parts of the body and humidity response of wet cotton balls, (c) degree of moisture dissipation of various parts of the body, (d) corresponding amplitude of different distances between the palm and PLFC, (e) physical display of hot and cold water below PLFC, (f) the response of hot water and cold water in PLFC.

總結與展望

本文提出一種基于紙的濕度傳感器PLFC，以A4紙為基底結合PFCTe制備而成，具有寬檢測范圍、高靈敏度、快速響應、高穩(wěn)定性及線性度等特點，其工作機理涉及離子移動與水分子反應，通過特殊結構和材料特性實現對濕度的敏感響應，在傳感器制造與性能表征方面有詳細闡述，性能測試顯示其在不同濕度條件下的良好表現，可用于呼吸和皮膚濕度監(jiān)測，在呼吸監(jiān)測中能區(qū)分不同呼吸模式，在皮膚濕度監(jiān)測中能感知不同身體部位濕度及水分蒸發(fā)情況，對健康監(jiān)測和疾病追蹤有重要意義，且制備成本低適合大規(guī)模生產，在可穿戴醫(yī)療技術領域有潛在應用前景。

文獻鏈接：https://pubs.rsc.org/en/Content/ArticleLanding/2024/TA/D4TA05393A

審核編輯 黃宇