Wu Jia-Kang, Wu En-Kang, Kim Nam-Young, Kim Eun-Seong, Gu Xiao-Feng, Liang Jun-Ge
School of Integrated Circuits, Jiangnan University, Wuxi 214122, China.
RFIC Center, Kwangwoon University, Seoul 139-701, Republic of Korea.
ACS Sens. 2024 Sep 27;9(9):4731-4739. doi: 10.1021/acssensors.4c01108. Epub 2024 Aug 21.
Microwave gas sensors have garnered attention for their high sensitivity and selectivity in the detection of volatile organic compounds (VOCs). However, traditional gas sensors generally rely on sensitive materials that degrade over time and are easily affected by the environment, compromising their stability and accuracy. This study proposes a microwave VOC gas sensor based on the condensation effect. The sensor adopts a novel design without sensitive materials, utilizing the condensation effect to detect acetone gas. The sensor system consists of a microwave sensor and a temperature control device. As the sensor temperature is lowered below the boiling point of acetone, the condensation of acetone gas on the sensor surface is achieved, enabling accurate detection of acetone gas. Experimental results indicate that the accumulated amount of acetone on the sensor surface is positively correlated with its response, with the maximum response of 3000 ppm acetone gas reaching 0.34 dB. Additionally, this study investigated the detection mechanism of the sensor after adding the sensitive material MXene and compared the performance of the sensor at different temperatures (-10 °C, 0 °C, and 60 °C). The results show that at -10 °C the sensor mainly captures acetone through physical adsorption, while at 25 and 60 °C, it primarily responds through chemical adsorption, with a maximum response of 0.29 dB. The VOC sensor based on the condensation effect without sensitive materials not only achieves the same sensitivity as traditional microwave sensors but also demonstrates stronger stability and anti-interference capabilities.
微波气体传感器因其在检测挥发性有机化合物（VOCs）方面的高灵敏度和选择性而受到关注。然而，传统气体传感器通常依赖于随着时间推移会降解且容易受到环境影响的敏感材料，这会损害其稳定性和准确性。本研究提出了一种基于冷凝效应的微波VOC气体传感器。该传感器采用了一种无敏感材料的新颖设计，利用冷凝效应来检测丙酮气体。传感器系统由一个微波传感器和一个温度控制装置组成。当传感器温度降低到丙酮沸点以下时，丙酮气体在传感器表面实现冷凝，从而能够准确检测丙酮气体。实验结果表明，传感器表面丙酮的累积量与其响应呈正相关，3000 ppm丙酮气体的最大响应达到0.34 dB。此外，本研究还研究了添加敏感材料MXene后传感器的检测机制，并比较了传感器在不同温度（-10°C、0°C和60°C）下的性能。结果表明，在-10°C时，传感器主要通过物理吸附捕获丙酮，而在25°C和60°C时，它主要通过化学吸附响应，最大响应为0.29 dB。基于冷凝效应且无敏感材料的VOC传感器不仅实现了与传统微波传感器相同的灵敏度，还表现出更强的稳定性和抗干扰能力。
