Electrospun CeO₂ nanoparticles/PVP nanofibers based high-frequency surface acoustic wave humidity sensor

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• 作者：Yuan LiuAuthor Vitae ; Hui HuangAuthor Vitae ; Lingling WangAuthor Vitae ; Daoping CaiAuthor Vitae ; Bin LiuAuthor Vitae ; Dandan WangAuthor Vitae ; Qiuhong LiAuthor Vitae ; Taihong Wang ; ^{thwang@xmu.edu.cn" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：Surface acoustic wave ; High frequency ; Humidity sensor ; CeO2 nanoparticles ; PVP nanofibers
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2016
• 出版时间：February 2016
• 年：2016
• 卷：223
• 期：Complete
• 页码：730-737
• 全文大小：2665 K

文摘

Nowadays the working frequencies of surface acoustic wave (SAW) sensors are usually not higher than 500 MHz, typically in the range of a few dozen to hundred megahertz, while an increase of working frequency should be beneficial to the sensor performance. Thus, a high frequency SAW resonator operating at 1.56 GHz was fabricated for relative humidity (RH) detection. The CeO₂ nanoparticles (NPs)/polyvinylpyrrolidone (PVP) nanofibers were prepared by electrospinning of PVP solution with CeO₂ NPs working as the sensitive layer. The inorganic CeO₂ NPs were synthesized previously using a hydrothermal method. In contrast with SAW sensor working at lower resonant frequency (879 MHz), the resonant frequency shift of the sensor based on 1.56 GHz was about −2.5 MHz in the RH range of 11% to 95%, which was approximately 8 times of the former one. Further analysis demonstrated that the additional acoustoelectric loading effect arising from increased electrical conductivity of CeO₂/PVP nanofibers in high RH improved the frequency response compared with pure PVP nanofibers based SAW sensor. Moreover, the SAW sensor based on inorganic/organic nanohybrid also showed high stability under humid environment and negligible cross-sensitivity effects ensuring further wireless humidity detection.