Anodic Aluminum Oxide-Based Chemi-Capacitive Sensor for Ethanol Gas

Gi-Hwan Lim; In-Yea Kim; Ji-Young Park; Yong-Ho Choa; Jae-Hong Lim

doi:10.3390/nano14010070

Anodic Aluminum Oxide-Based Chemi-Capacitive Sensor for Ethanol Gas

Nanomaterials (Basel). 2023 Dec 26;14(1):70. doi: 10.3390/nano14010070.

Authors

Gi-Hwan Lim¹, In-Yea Kim¹, Ji-Young Park², Yong-Ho Choa², Jae-Hong Lim¹

Affiliations

¹ Department of Materials Science and Engineering, Gachon University, Seongnam-si 13120, Republic of Korea.
² Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588, Republic of Korea.

Abstract

Alcohol ingested by humans can be analyzed via breath tests; however, approximately 1% can be excreted via the skin. In this paper, we present a capacitive sensor using hydrophobically treated anodic aluminum oxide (AAO) capable of detecting alcohol excreted through the epidermis. The degree of hydrophobicity based on the duration of exposure to 3-aminopropyltriethoxysilane vapor comprising a small number of Si-NH₂ functional groups on the AAO surface was confirmed and the optimal exposure time was confirmed to be 60 min. The hydrophobized AAO showed a 4.8% reduction in sensitivity to moisture. Simultaneously, the sensitivity of the sensor to ethanol decreased by only 12%. Lastly, the fabricated sensor was successfully operated by attaching it to an ankle-type breathalyzer.

Keywords: AAO; capacitive sensor; sensor; surface modification.

Grants and funding

This research was funded by the Korea Environmental Industry Technology Institute (grant number P0026243) and the Korea Institute for Advancement of Technology (grant number P0026243).