Kirigami-inspired gas sensors for strain-insensitive operation

• DOI: 10.1016/j.rineng.2024.101805
• Publication Date: 2024-01-20T02:11:05Z
• Authors: Jeonhyeong Park; Hyeoncheol Lim; Junwoo Yea; Chaehyun Ryu; Soon In Jung; Runia Jana; Kyung-In Jang; Hohyun Keum; Hoe Joon Kim
• Keywords: WEARABLE GAS; Technology; Kirigami; H2S; T; PERFORMANCE; OXIDATION; 540; NANOCOMPOSITES; 01 natural sciences; LAYERS; 620; 0104 chemical sciences; REMOVAL; GRAPHENE OXIDE RGO; Gas sensor; Functionalization; Flexible

Wearable electronics for the Internet of Things (IoT) have spurred interest in optimizing stretchable substrates, electrodes, and sensing materials. Specifically, wearable gas sensors are valuable for real-time monitoring of hazardous chemicals. For wearable gas sensors, a stable operation under mechanical deformation is required. Here, we introduce strain-insensitive Kirigami-structured gas sensors decorated with titanium dioxide (TiO2) functionalized carbon nanotubes (CNTs) for NO2 sensing. The Kirigami-shaped substrate is used to ensure mechanical stability when stretched. The developed device shows only a 1.3 % change in base resistance under 80 % strain. In addition, the impact of electro-thermal properties at various strain levels is analyzed to aid the understanding of the device's performance. The CNT-TiO2 composite induced alterations in p-n heterojunctions, improving the measurement sensitivity by approximately 250 % compared to a bare CNT sensor. Additionally, the sensors exhibited a 10-fold faster desorption rate due to the enhanced photocatalytic effect of TiO2 under UV exposure. Remarkably, the Kirigami-structured gas sensors maintained stable and repetitive sensing operation even under 80 % strain, which would be enough to be used in various wearable applications.