An ultra-small integrated CO2 infrared gas sensor for wearable end-tidal CO2 monitoring

Liyang Feng; Yanxiang Liu; Yi Wang; Hong Zhou; Ming Wu; Tie Li

doi:10.1016/j.isci.2023.108293

An ultra-small integrated CO₂ infrared gas sensor for wearable end-tidal CO₂ monitoring

iScience. 2023 Oct 23;26(11):108293. doi: 10.1016/j.isci.2023.108293. eCollection 2023 Nov 17.

Authors

Liyang Feng^{1

2}, Yanxiang Liu¹, Yi Wang¹, Hong Zhou¹, Ming Wu¹, Tie Li¹

Affiliations

¹ State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
² University of Chinese Academy of Sciences (UCAS), Beijing 100049, China.

Abstract

Human physiological metabolic status can be obtained by monitoring exhaled CO₂ concentration, but current CO₂ sensors have disadvantages such as large size, high power consumption, and slow response time, which limit their application in wearable devices and portable instruments. In this article, we report a small size, good performance, and large range CO₂ infrared gas sensor that integrates a high emissivity MEMS emitter chip, a high detectivity thermopile chip, and a high coupling efficiency optical chamber to achieve high efficiency optical-thermal-electrical conversion. Compared with typical commercial sensors, the size of the sensor can be reduced by approximately 80% to only 10 mm × 10 mm × 6.5 mm, with the advantages of low power consumption and fast response speed. Further, a monitoring system for end-tidal CO₂ concentration installed on a mask was developed using this sensor, and good results were achieved.

Keywords: Health technology; Materials application.