SENSORS
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2025
·Vol. 25
·期 9
·2634
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IF 3.5
Mengxue Xu,Yihong Zhong,Hongpeng Zhang,Yi Tao,Qingqing Shen,Shumin Zhang,Pingping Zhang,Xiaochun Hu,Xingqi Liu,Xuhui Sun,Zhenxing Cheng
HighlightsWhat are the main findings?The problem of dichloromethane “poisoned” MOS materials was well solved.Gas sensing mechanism of dichloromethane on the MOS material was elucidate.What is the implication of the main finding?The best performance of significant response and excellent recoverability by the MEMS sensor to dichloromethane is attributed to a synergetic effect from Mo and Ni co-doping into SnO2.Kinetically, the transportation of dichloromethane molecules onto the surface determines the response process. Thermodynamically, the output steady electronic signal of the MEMS sensor follows the equations newly derived by statistical mechanics.The challenging problem of chlorine “poisoning” SnO2for poorly recoverable detection of dichloromethane has been solved in this work. The materials synthesized by Ni or/and Mo doping SnO2were spread onto the micro-hotplates (<1 mm3) to fabricate the MEMS sensors with a low power consumption (<45 mW). The sensor based on Mo·Ni co-doped SnO2is evidenced to have the best sensing performance of significant response and recoverability to dichloromethane between 0.07 and 100 ppm at the optimized temperature of 310 °C, in comparison with other sensors in this work and the literature. It can be attributed to a synergetic effect of Mo·Ni co-doping into SnO2as being supported by characterization of geometrical and electronic structures. The sensing mechanism of dichloromethane on the material is investigated. In situ infrared spectroscopy (IR) peaks identify that the corresponding adsorbed species are too strong to desorb, although it has demonstrated a good recoverability of the material. A probable reason is the formation rates of the strongly adsorbed species are much slower than those of the weakly adsorbed species, which are difficult to form significant IR peaks but easy to desorb, thus enabling the material to recover. Theoretical analysis suggests that the response process is kinetically determined by molecular transport onto the surface due to the free convection from the concentration gradient during the redox reaction, and the output steady voltage thermodynamically follows the equation only formally identical to the Langmuir–Freundlich equation for physisorption but is newly derived from statistical mechanics.
研究领域:
材料科学
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传感器技术
·
物理化学
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产品关联
DOI
PubMed
高影响因子
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
·
2024
·
IF 5.6
Chenyang Yu,Jianhong Liu,Hongchao Zhao,Mengqing Wang,Jing Li,Xiaopeng She,Yi Chen,Yangjie Wang,Bochao Liu,Cheng Zou,Yong He,Yong Zhou
Acetone plays a critical role in environmental protection and human healthcare, thus necessitating sensitive and selective detection. In this regard, a resistive microelectromechanical system (MEMS) acetone sensor featuring a sensing layer of
$\alpha $
-Fe2O3 nanoparticles modified tungsten trioxide (WO3) nanoplates is utilized in this work. After optimizing the composition proportion and operating temperature, the Fe/W:0.2 sensor delivered a wide detection range (0.05–80 ppm), and an approximately sevenfold higher response of 40.6 toward 10 ppm acetone at
$217~^{\circ }$
C than pure WO3 analog. In addition, a limit of detection (LoD) of 50 ppb was achieved, which ranks among the lowest cases thus far. Together with excellent repeatability, selectivity, and long-term stability, the sensor also showed a humidity-enhanced response. This work offers an alternative strategy to realize trace acetone detection within high-humidity conditions and showcases a huge application potential in exhaled breath-involving diabetes monitoring in the future.
研究领域:
材料科学
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医学
·
环境科学
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产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Yu Bing,Zhao Song,Hongtao Jiang,Xiaoyi Xu,Zhongzheng Yu,Tingting Zhou,Tong Zhang
Water competitive adsorption and limited reaction sites on the micro-scale sensing area of micro-electro-mechanical system (MEMS) sensors are two bottleneck problems that restrict the detection of trace indoor polluted gases, leading to drifting and weak signals. To address this, a “duet-insurance” sensing strategy is proposed to protect and amplify the sensing signal. For the first-level protection, the well-designed double-layer structure consisting of Janus TpMa covalent organic framework (COF)/Eu-doped α-Fe 2 O 3 can resist diffusion of water molecules and facilitate the electron transfer from formaldehyde (CH 2 O) to sensing layers, benefiting from the outer hydrophobic character of Janus TpMa and the strong CH 2 O adsorption capacity of Eu-doped Fe 2 O 3 . For the second-level amplification, the unique variable temperature excitation facilitates the deep penetration of CH 2 O into the active sites across COF layers, enabling signal amplification through thermally actuated carrier modulation. The sensor demonstrates high sensing ability to the CH 2 O, with an ultra-low limit of detection of 794 ppt. Leveraging the novel sensing strategy, a multi-functional, visual sensing system is designed to identify multi-indoor pollution gases by feature signal encoding and color mapping, showcasing the promising potential for MEMS sensors based on Janus TpMa COF/Eu-doped α-Fe 2 O 3 materials.
研究领域:
材料科学
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环境科学
·
化学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Wenjun Yan,Yun Liu,Yan Bai,Yulong Chen,Houpan Zhou,Waqar Ahmad
In this paper, we present the design and evaluation of an intelligent MEMS sensor employing the oxidized medium-entropy alloy (O-MEA) of FeCoNi as the gas-sensing material. Due to the specific catalytic exothermic reaction of the O-MEA on H2/CO, the sensor shows great selectivity for H2 and CO at 150 °C of the integrated microheater in the MEMS device, with the theoretical detection limit of 0.3 ppm for H2 and 0.29 ppm for CO. The MEMS heater, capable of instantaneous temperature changes in pulse operation mode, offers a novel approach for thermal modulation of the sensor, which is crucial for the adsorption and reaction of H2/CO molecules on the sensing layer surface. Consequently, we investigate the gas-sensing capabilities of the sensor under pulse heating modes (PHMs) of the MEMS heater and then propose the gas-sensing mechanism. The results indicate that PHMs significantly not only reduce the operating temperature and power consumption but also enhance the sensor’s functionality by providing multivariable response signals, paving the way for intelligent gas detection. Based on the high selectivity to H2 and CO, transforming the transient sensing curves into two-dimensional images via Gramian Angular Field (GAF) model and subsequent modeling using a convolutional neural network (CNN) algorithm, we have realized efficient and intelligent recognition of H2 and CO. This work provides insight for the development of low-power, high-performance MEMS gas sensors and further intelligence of individual MEMS sensors.
研究领域:
材料科学
·
传感器技术
·
人工智能
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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