Improvement on Potential Drifting for Sol-Gel and Electroplated Iridium Oxide-Based pH-Sensing Films

被引：2

作者：

Chawang, Khengdauliu ^{[1
]}

Xia, Xing ^{[2
]}

Huang, Mao-Hsiang ^{[2
]}

Bing, Sen ^{[1
]}

Benomar, Mohamed ^{[2
]}

Doan, Gabriella ^{[1
]}

Cao, Hung ^{[2
]}

Chiao, J. -C. ^{[1
]}

机构：

[1] Southern Methodist Univ, Dept Elect & Comp Engn, Dallas, TX 75206 USA

[2] Univ Calif Irvine, Dept Elect Engn & Comp Sci, Irvine, CA 92697 USA

来源：

IEEE SENSORS LETTERS | 2023年 / 7卷 / 09期

关键词：

Sensor materials; potential drift; flexible; pH characterization; pH sensors; STABILITY;

D O I：

10.1109/LSENS.2023.3307110

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

This letter investigates the use of external voltage resets to reduce drifting issues of iridium oxide (IrOx) pH-sensing films. Two types of IrOx films prepared by sol-gel and electroplating techniques were examined comparing hydrous and anhydrous material characteristics. The thin-film IrOx allows inexpensive processing for flexible polyimide substrates enabling planar and monolithic integration for wearables and miniature pH sensors. Open-circuit potential drifts and external voltage resets were investigated for freshly prepared electrodes and retested after 14 days. External resets were examined at different voltage levels. Sol-gel electrodes showed 57% and 81% drift improvement in acid and alkaline test solutions, respectively, while electroplated ones showed 84% and 88% improvement. Sensitivity and hysteresis were investigated after external resets and showed promising results. A total of 15 sol-gel and 15 electroplated electrodes were characterized. Differences in pH characteristics are attributed to different types of IrOx compositions. The quicker response transitions and reduced potential drifts will enable reliable long-term pH monitoring and reduce frequent calibration for pH-sensing applications.

引用

页数：4