Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layer
A low-cost and environment-friendly surface acoustic wave (SAW) humidity sensor was fabricated on a quartz substrate using sol-gel/spin-coated sodium alginate (SA) sensing layer. The sensing mechanism is based on the frequency shift of the SAW sensor caused by both mass loading and electrical loadin...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-06-01
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| Series: | Micro and Nano Engineering |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2590007222000247 |
| _version_ | 1811257567300550656 |
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| author | Y.C. Han X.Y. Kong W. Wu J.S. Li X. Yang Y.J. Guo Y.Q. Fu Hamdi Torun X. Xiang Y.L. Tang X.T. Zu |
| author_facet | Y.C. Han X.Y. Kong W. Wu J.S. Li X. Yang Y.J. Guo Y.Q. Fu Hamdi Torun X. Xiang Y.L. Tang X.T. Zu |
| author_sort | Y.C. Han |
| collection | DOAJ |
| description | A low-cost and environment-friendly surface acoustic wave (SAW) humidity sensor was fabricated on a quartz substrate using sol-gel/spin-coated sodium alginate (SA) sensing layer. The sensing mechanism is based on the frequency shift of the SAW sensor caused by both mass loading and electrical loading, with the former being the dominant factor. The SA film prepared in this study is an environment-friendly material with a large number of hydroxyl and carboxylate groups, which easily adsorb and react with H2O molecules to form hydrogen bonds. These adsorbed H2O molecules lead to significantly enhanced mass loading and signal responses of the SAW sensor. Electrical loading effect is also generated due to the transfer of hydrogen ions in the H2O molecules, which alters the electrical resistance and results in changes of resonant frequencies of the SAW device. When the relative humidity (RH) is increased from 35% to 85%, the responses of the SAW sensor with 1 wt% SA are significantly decreased. Whereas in a low humidity environment (e.g., RH <35%), the responses of the sensor show a linear relationship with the change of humidity. The developed humidity sensor shows good short-term/long-term stabilities and a low temperature coefficient of frequency. |
| first_indexed | 2024-04-12T17:59:34Z |
| format | Article |
| id | doaj.art-ae36e261907e4a2fa21653dd23bd112c |
| institution | Directory Open Access Journal |
| issn | 2590-0072 |
| language | English |
| last_indexed | 2024-04-12T17:59:34Z |
| publishDate | 2022-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Micro and Nano Engineering |
| spelling | doaj.art-ae36e261907e4a2fa21653dd23bd112c2022-12-22T03:22:13ZengElsevierMicro and Nano Engineering2590-00722022-06-0115100127Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layerY.C. Han0X.Y. Kong1W. Wu2J.S. Li3X. Yang4Y.J. Guo5Y.Q. Fu6Hamdi Torun7X. Xiang8Y.L. Tang9X.T. Zu10School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, PR ChinaSchool of Physics, University of Electronic Science and Technology of China, Chengdu 610054, PR ChinaSchool of Physics, University of Electronic Science and Technology of China, Chengdu 610054, PR ChinaInstitute of Chemical materials, China Academy of Engineering Physics, Mianyang 621900, PR ChinaInstitute of Chemical materials, China Academy of Engineering Physics, Mianyang 621900, PR ChinaSchool of Physics, University of Electronic Science and Technology of China, Chengdu 610054, PR China; Corresponding authors.Faculty of Engineering & Environment, University of Northumbria, Newcastle upon Tyne NE1 8ST, UKFaculty of Engineering & Environment, University of Northumbria, Newcastle upon Tyne NE1 8ST, UKSchool of Physics, University of Electronic Science and Technology of China, Chengdu 610054, PR ChinaSchool of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, PR ChinaSchool of Physics, University of Electronic Science and Technology of China, Chengdu 610054, PR China; Corresponding authors.A low-cost and environment-friendly surface acoustic wave (SAW) humidity sensor was fabricated on a quartz substrate using sol-gel/spin-coated sodium alginate (SA) sensing layer. The sensing mechanism is based on the frequency shift of the SAW sensor caused by both mass loading and electrical loading, with the former being the dominant factor. The SA film prepared in this study is an environment-friendly material with a large number of hydroxyl and carboxylate groups, which easily adsorb and react with H2O molecules to form hydrogen bonds. These adsorbed H2O molecules lead to significantly enhanced mass loading and signal responses of the SAW sensor. Electrical loading effect is also generated due to the transfer of hydrogen ions in the H2O molecules, which alters the electrical resistance and results in changes of resonant frequencies of the SAW device. When the relative humidity (RH) is increased from 35% to 85%, the responses of the SAW sensor with 1 wt% SA are significantly decreased. Whereas in a low humidity environment (e.g., RH <35%), the responses of the sensor show a linear relationship with the change of humidity. The developed humidity sensor shows good short-term/long-term stabilities and a low temperature coefficient of frequency.http://www.sciencedirect.com/science/article/pii/S2590007222000247Surface acoustic wave, sensorSodium alginate (SA)Humidity |
| spellingShingle | Y.C. Han X.Y. Kong W. Wu J.S. Li X. Yang Y.J. Guo Y.Q. Fu Hamdi Torun X. Xiang Y.L. Tang X.T. Zu Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layer Micro and Nano Engineering Surface acoustic wave, sensor Sodium alginate (SA) Humidity |
| title | Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layer |
| title_full | Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layer |
| title_fullStr | Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layer |
| title_full_unstemmed | Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layer |
| title_short | Environment-friendly surface acoustic wave humidity sensor with sodium alginate sensing layer |
| title_sort | environment friendly surface acoustic wave humidity sensor with sodium alginate sensing layer |
| topic | Surface acoustic wave, sensor Sodium alginate (SA) Humidity |
| url | http://www.sciencedirect.com/science/article/pii/S2590007222000247 |
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