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The Ta2O5 thin film has an amorphous microstructure, and its surface roughness is less than 3.17 nm. A signal processing circuit and a software filtering algorithm are also designed to measure the pH value, thus improving the detection accuracy and anti-interference ability. Good linearity (R2 = 0.99904) and sensitivity (63.12 mV\/pH) are recorded for the proposed sensing element in the range of pH 2~12. In addition, the sensor\u2019s drift and hysteresis are equal to 5.1 mV and 5.8 mV, respectively. The enhanced sensing performance in combination with the facile miniaturization process, low fabrication cost, and suitability for mass production render the fabricated sensor attractive for applications where pH change measurements in a water environment are required.<\/jats:p>","DOI":"10.3390\/s23136061","type":"journal-article","created":{"date-parts":[[2023,7,3]],"date-time":"2023-07-03T00:53:16Z","timestamp":1688345596000},"page":"6061","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Fabrication and Performance of a Ta2O5 Thin Film pH Sensor Manufactured Using MEMS Processes"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6521-4745","authenticated-orcid":false,"given":"Yuzhen","family":"Guo","sequence":"first","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, North University of China, Taiyuan 030051, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4726-4287","authenticated-orcid":false,"given":"Zengxing","family":"Zhang","sequence":"additional","affiliation":[{"name":"Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China"},{"name":"Tan Kah Kee Innovation Laboratory, Xiamen 361005, China"}]},{"given":"Bin","family":"Yao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, North University of China, Taiyuan 030051, China"}]},{"given":"Jin","family":"Chai","sequence":"additional","affiliation":[{"name":"Xiamen Zehuo Industry Digital Research Institute Co., Ltd., Xiamen 361005, China"}]},{"given":"Shiqiang","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, North University of China, Taiyuan 030051, China"}]},{"given":"Jianwei","family":"Liu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, North University of China, Taiyuan 030051, China"}]},{"given":"Zhou","family":"Zhao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, North University of China, Taiyuan 030051, China"}]},{"given":"Chenyang","family":"Xue","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Dynamic Measurement Technology, North University of China, Taiyuan 030051, China"},{"name":"Tan Kah Kee Innovation Laboratory, Xiamen 361005, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,6,30]]},"reference":[{"key":"ref_1","unstructured":"Zheng, N., Huo, C., Xu, X., Zang, K., Mu, J., Zhao, H., and Wang, J. (2018). Progress of pH Determination in the Context of Ocean Acidification. Ocean. Dev. Manag., 24\u201329."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"100635","DOI":"10.1016\/j.pmatsci.2019.100635","article-title":"Metal oxides based electrochemical pH sensors: Current progress and future perspectives","volume":"109","author":"Manjakkal","year":"2020","journal-title":"Prog. Mater. Sci."},{"key":"ref_3","unstructured":"Qu, B., Song, J., and Li, X. (2020). Advances in ocean acidification time-series studies. Mar. Sci. Bull., 281\u2013290."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1038\/nature04095","article-title":"Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms","volume":"437","author":"Orr","year":"2005","journal-title":"Nature"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"571301","DOI":"10.3389\/fmars.2020.571301","article-title":"Enhance Ocean Carbon Observations: Successful Implementation of a Novel Autonomous Total Alkalinity Analyzer on a Ship of Opportunity","volume":"7","author":"Seelmann","year":"2020","journal-title":"Front. Mar. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1021\/acssensors.0c00031","article-title":"Ultrasensitive Seawater pH Measurement by Capacitive Readout of Potentiometric Sensors","volume":"5","author":"Kraikaew","year":"2020","journal-title":"ACS Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.aca.2016.05.012","article-title":"X-ray photoelectron spectroscopic and electrochemical impedance spectroscopic analysis of RuO2-Ta2O5 thick film pH sensors","volume":"931","author":"Manjakkal","year":"2016","journal-title":"Anal. Chim. Acta"},{"key":"ref_8","first-page":"423","article-title":"CIP (cleaning-in-place) suitable \u201cnon-glass\u201d pH sensor based on a Ta2O5-gate EIS structure","volume":"111\u2013112","author":"Brinkmann","year":"2005","journal-title":"Sens. Actuators B Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"746","DOI":"10.1007\/s10008-006-0120-4","article-title":"pH Monitoring: A review","volume":"10","author":"Vonau","year":"2006","journal-title":"J. Solid State Electrochem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1016\/j.snb.2013.10.129","article-title":"Electrochemical impedance spectroscopy study of Ta2O5 based EIOS pH sensors in acid environment","volume":"192","author":"Chen","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1016\/j.talanta.2015.09.069","article-title":"Potentiometric RuO2-Ta2O5 pH sensors fabricated using thick film and LTCC technologies","volume":"147","author":"Manjakkal","year":"2016","journal-title":"Talanta"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4955","DOI":"10.3390\/s90604955","article-title":"Metal Oxides and Ion-Exchanging Surfaces as pH Sensors in Liquids: State-of-the-Art and Outlook","volume":"9","author":"Kurzweil","year":"2009","journal-title":"Sensors"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1080\/10408348908048815","article-title":"Metal-Metal Oxide and Metal Oxide Electrodes as pH Sensors","volume":"21","author":"Glab","year":"1989","journal-title":"Crit. Rev. Anal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/0925-4005(94)87044-6","article-title":"Comparison of the hysteresis of Ta2O5 and Si3N4, pH-sensing insulators","volume":"17","author":"Bousse","year":"1994","journal-title":"Sens. Actuators B"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Becker, T., Arshak, K., Can\u00e9, C., Gill, E., Korostynska, O., Barker, N.S., and Arshak, A. (2007, January 2\u20134). Mixed metal oxide films as pH sensing materials. Proceedings of the Smart Sensors, Actuators, and MEMS III, Gran Canaria, Spain.","DOI":"10.1117\/12.721950"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"B60","DOI":"10.1149\/1.1850362","article-title":"An Investigation of Structures of Thermal and Anodic Tantalum Oxide Films","volume":"152","author":"Maeng","year":"2005","journal-title":"J. Electrochem. Soc."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"770","DOI":"10.1002\/elan.201400571","article-title":"Microstructural, Impedance Spectroscopic and Potentiometric Analysis of Ta2O5 Electrochemical Thick Film pH Sensors","volume":"27","author":"Manjakkal","year":"2015","journal-title":"Electroanalysis"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"704","DOI":"10.1007\/s40145-021-0465-2","article-title":"Annealing effects on the optical and electrochemical properties of tantalum pentoxide films","volume":"10","author":"Ren","year":"2021","journal-title":"J. Adv. Ceram."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1016\/j.mseb.2004.12.055","article-title":"Comparision of residual stress and optical properties in Ta2O5 thin films deposited by single and dual ion beam sputtering","volume":"118","author":"Yoon","year":"2005","journal-title":"Mater. Sci. Eng. B"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"9758","DOI":"10.1016\/j.jallcom.2011.08.019","article-title":"Electrical and optical properties of tantalum oxide thin films prepared by reactive magnetron sputtering","volume":"509","author":"Wei","year":"2011","journal-title":"J. Alloys Compd."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"756","DOI":"10.3390\/coatings4040756","article-title":"Recent Developments in R.F. Magnetron Sputtered Thin Films for pH Sensing Applications\u2014An Overview","volume":"4","author":"Maurya","year":"2014","journal-title":"Coatings"},{"key":"ref_22","unstructured":"Gu, M., Hu, S., Peng, R., Li, Y., Chen, J., Yuan, X., and Qiu, M. (2013, January 25\u201327). A review of developments in the preparation methods of tantalum pentoxide film. Proceedings of the International Symposium on Photoelectronic Detection and Imaging 2013: Micro\/Nano Optical Imaging Technologies and Applications, Beijing, China."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"954","DOI":"10.1002\/cta.2618","article-title":"Modeling and simulation of temperature drift for ISFET-based pH sensor and its compensation through machine learning techniques","volume":"47","author":"Bhardwaj","year":"2019","journal-title":"Int. J. Circuit Theory Appl."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4643","DOI":"10.3390\/s100504643","article-title":"A novel pH-dependent drift improvement method for zirconium dioxide gated pH-ion sensitive field effect transistors","volume":"10","author":"Chang","year":"2010","journal-title":"Sensors"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Nograles, A.H., Cruz, J.C.D., and Chung, W.-Y. (2021, January 26). pH ISFET Stabilization Time Measurement Analysis and Its Readout and Control Circuit. Proceedings of the 2021 IEEE International Conference on Automatic Control & Intelligent Systems (I2CACIS), Shah Alam, Malaysia.","DOI":"10.1109\/I2CACIS52118.2021.9495849"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3761","DOI":"10.1109\/TED.2020.3009646","article-title":"Characterizations of Electrolyte\u2013Insulator\u2013Semiconductor Sensors With Array Wells and a Stack-Sensing Membrane","volume":"67","author":"Chen","year":"2020","journal-title":"IEEE Trans. Electron Devices"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1805","DOI":"10.1109\/T-ED.1979.19690","article-title":"Basic Properties of the Electrolyte-SiO2-Si System: Physical and Theoretical Aspects","volume":"26","author":"Siu","year":"1979","journal-title":"IEEE Trans. Electron Devices"},{"key":"ref_28","first-page":"1807","article-title":"Faraday Transactions. Site-binding model of the electrical double layer at the oxide\/water interface","volume":"70","author":"Yates","year":"1974","journal-title":"J. Chem. Soc. Faraday Trans. Phys. Chem. Condens. Phases"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/0250-6874(84)80028-1","article-title":"The role of buried OH sites in the response mechanism of inorganic-gate pH-sensitive ISFETs","volume":"1","author":"Bousse","year":"1984","journal-title":"Sens. Actuators"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"596","DOI":"10.1038\/s41928-018-0162-5","article-title":"A wearable pH sensor with high sensitivity based on a flexible charge-coupled device","volume":"1","author":"Nakata","year":"2018","journal-title":"Nat. Electron."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"551","DOI":"10.1016\/S0925-4005(97)00156-1","article-title":"Determination of the pHpzc of insulators surface from capacitance\u2013voltage characteristics of MIS and EIS structures","volume":"44","author":"Poghossian","year":"1997","journal-title":"Sens. Actuators B Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"8700","DOI":"10.1021\/acs.analchem.8b02145","article-title":"Capacitive Model for Coulometric Readout of Ion-Selective Electrodes","volume":"90","author":"Jarolimova","year":"2018","journal-title":"Anal. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.sna.2017.10.013","article-title":"A review of screen-printed silver\/silver chloride (Ag\/AgCl) reference electrodes potentially suitable for environmental potentiometric sensors","volume":"267","author":"Sophocleous","year":"2017","journal-title":"Sens. Actuators A Phys."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"070529","DOI":"10.1149\/1945-7111\/ac10f6","article-title":"Enhanced Capacitive Performance of Mesoporous Vanadium Nitride Nanobelts","volume":"168","author":"Zhou","year":"2021","journal-title":"J. Electrochem. Soc."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/13\/6061\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:03:50Z","timestamp":1760126630000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/13\/6061"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,6,30]]},"references-count":34,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2023,7]]}},"alternative-id":["s23136061"],"URL":"https:\/\/doi.org\/10.3390\/s23136061","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,6,30]]}}}