scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Fabrication of Microsensor for Detection of Low-Concentration Formaldehyde Gas in Formalin-Treated Fish

01 Dec 2020-IEEE Transactions on Electron Devices (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 67, Iss: 12, pp 5710-5716
TL;DR: In this paper, an ultrafast direct laser patterning technique was used to fabricate a low-cost microsensor and its application for formaldehyde detection was reported, where the patterns of microheater and interdigitated electrodes (IDEs) were realized using laser micromachining techniques by ablation of gold thin film on alumina substrate.
Abstract: Here, an ultrafast direct laser patterning technique to fabricate a low-cost microsensor and its application for formaldehyde detection are reported. The patterns of microheater and interdigitated electrodes (IDEs) were realized using laser micromachining techniques by ablation of gold thin film on alumina substrate. The thin film of gold microheater showed good stability up to 300 °C with a fast response time of 80 s and temperature coefficient of resistance (TCR) was calculated as $1.37\times 10^{-{3}}/^{\circ }\text{C}$ . Moreover, gold microheater exhibited long-term reliability under self-heating mode with a negligible resistance drift $^{-{1}}$ ) to formaldehyde even to detect sub-ppm concentrations with fast response (32 s) and recovery kinetics (72 s). Moreover, the microsensor was also used on-site rapid screening for the detection and quantification of formaldehyde concentration in formalin-treated fish sample.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, a highly sensitive and selective gas sensor for detecting formaldehyde is reported based on SnO2/ZnO heterospheres designed by atomic layer deposition (ALD).
Abstract: Heterostructures of metal oxide semiconductors have a great promise for chemical gas sensors due to the peculiar properties at the heterointerface. In this work, a highly sensitive and selective gas sensor for detecting formaldehyde is reported based on SnO2/ZnO heterospheres designed by atomic layer deposition (ALD). The electronic properties at the SnO2/ZnO heterointerface can be modulated by optimizing the loading of ZnO through changing ALD cycles. Gas sensing tests indicate that the ZnO ALD significantly improved the sensor properties including higher responses, faster response-recovery dynamics and better selectivity. The response of the SnO2/ZnO sensor to 1 ppm formaldehyde (Ra/Rg = 9.7) shows 4 times enhancement compared to pristine SnO2 at a working temperature of 200 °C. ZnO ALD of 10 cycles leads to the best response and recovery dynamics (12 and 24 s), and that of 15 ALD cycles results in the highest response (Ra/Rg = 38.2) to 20 ppm formaldehyde. The SnO2/ZnO sensor also registers a low detection limit of 70 ppb, which allows for reliable detection of sub-ppm formaldehyde. The remarkable sensor performances indicate the ALD surface engineering is promising for the design of new materials for reliable detection of harmful molecules.

87 citations

Journal ArticleDOI
TL;DR: In this article, Fe2O3-sensitized SnO2 nanosheets are designed via atomic layer deposition (ALD) to realize high performance formaldehyde detection, by varying the ALD cycles, the influence of different Fe 2O3 loading on the sensing performance of SnO 2 nanOSheets is revealed.
Abstract: Metal oxide semiconductor (MOS) nanostructures have been widely explored for formaldehyde sensors. The low surface chemical and electronic properties of pure MOS, however, greatly limits the sensor functions. In this work, Fe2O3-sensitized SnO2 nanosheets are designed via atomic layer deposition (ALD) to realize high performance formaldehyde detection. By varying the ALD cycles, the influence of different Fe2O3 loading on the sensing performance of SnO2 nanosheets is revealed. It is found that Fe2O3 ALD can greatly boost the sensing performance and the SnO2 nanosheets with 20 Fe2O3 ALD cycles exhibits the best response (Ra/Rg = 4.5) and fast response and recovery dynamics (9 and 34 s) to 20 ppm formaldehyde at a relative low temperature of 220 °C. The sensor based on SnO2/Fe2O3 also displays good selectivity to formaldehyde as well as the reliable stability and low limit of detection (LOD). This work will shed some light to design efficient MOS heterostructures for detection of formaldehyde.

37 citations

Journal ArticleDOI
TL;DR: The significance of two-dimensional (2D) materials including graphene, and transition metal dichalcogenides has been escalating in gas sensor technology owing to detection of gases at room temperature (RT) and good performance as discussed by the authors .
Abstract: The significance of two-dimensional (2D) materials including graphene, and transition metal dichalcogenides has been escalating in gas sensor technology owing to detection of gases at room temperature (RT) and good...

1 citations

Journal ArticleDOI
TL;DR: In this paper , a research on the evaluation of adolescent lower limb posture correction based on collaborative filtering and microsensors is carried out, which simplifies the existing human body posture monitoring model and establishes a human body model with four degrees of freedom of the lower limbs.
Abstract: Automatic monitoring of physical activity provides reliable data support for the maintenance of people's physical health and provides more scientific data for studying the relationship between physical activity and disease. In this article, a research on the evaluation of adolescent lower limb posture correction based on collaborative filtering and microsensors is carried out. Aiming at the problem that the human body posture monitoring system needs multiple nodes, this article simplifies the existing human body posture monitoring model and establishes a human body model with four degrees of freedom of the lower limbs. On this basis, the micro-sensor assembly scheme and monitoring node layout scheme for obtaining model description parameters are determined. Methods such as collaborative filtering and support vector machines are used in the process of sensor data processing and correction effect evaluation. Finally, this article uses the constructed human body posture monitoring system to carry out the recognition test of the specific posture of the human body. The experimental results show that the evaluation scheme can effectively monitor and evaluate the effect of lower limb posture correction in adolescents.

1 citations

Journal ArticleDOI
TL;DR: In this article , density functional theory (DFT) analyzes the electronic structure of sensing materials and the adsorption energy of butyl acetate, and the effects of Ni element doping, oxygen vacancy constructions, and NiO quantum dot modifications on the modulation of the electronic structures of ZnO and on the ad-hoc energy of Butyl Acetate are investigated in detail.
References
More filters
Journal ArticleDOI
TL;DR: In this paper, the gas-sensing properties of the SnO2 nanoparticles, ZnO microrods and the nanocomposite of SnO 2 nanoparticles doped with 5-15% Zn O microrod were investigated.
Abstract: SnO2 nanoparticles and ZnO microrods were prepared and characterized by X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM). The results showed that the mean grain size of the SnO2 nanoparticles was 40 nm; the diameter of ZnO microrods was about 1–1.5 μm with a length between 8 and 10 μm. The gas-sensing properties of the SnO2 nanoparticles, ZnO microrods and the nanocomposite of SnO2 nanoparticles doped with 5–15 wt% ZnO microrods were investigated. The gas-sensing properties of the SnO2 nanoparticles were greatly improved by doping with the ZnO microrods. The SnO2–ZnO nanocomposite sensor showed high and quick response to trimethylamine (TMA) at 190–330 °C. This sensor showed the advantages of high selectivity, excellent sensitivity, strong stability and prompt response/recovery characteristics in detecting TMA at 330 °C. It could be used to detect the freshness of fishes.

197 citations


"Fabrication of Microsensor for Dete..." refers background in this paper

  • ...In recent years, some miscreant fish sellers of India and Bangladesh use formalin (aqueous solution of formaldehyde) during the transportation of fish to the market to avoid spoilage, and after consuming formalin-treated fish people suffer from various health issues [7]–[9]....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the formaldehyde content in different fish products was evaluated using a solid phase microextraction (SPME)-GC-MS method based on fiber derivatisation with pentafluorobenzyl-hydroxyl-amine hydrochloride.

192 citations

Journal ArticleDOI
TL;DR: In this paper, a non-linear exposure-response relationship was found for nasal cancer in rats, supporting a no-observed-adverse effect level (NOAEL) that allows setting a guideline value.
Abstract: Formaldehyde is a ubiquitous indoor air pollutant that is classified as “Carcinogenic to humans (Group 1)” (IARC, Formaldehyde, 2-butoxyethanol and 1-tert-butoxypropanol-2-ol. IARC monographs on the evaluation of carcinogenic risks to humans, vol 88. World Health Organization, Lyon, pp 39–325, 2006). For nasal cancer in rats, the exposure–response relationship is highly non-linear, supporting a no-observed-adverse-effect level (NOAEL) that allows setting a guideline value. Epidemiological studies reported no increased incidence of nasopharyngeal cancer in humans below a mean level of 1 ppm and peak levels below 4 ppm, consistent with results from rat studies. Rat studies indicate that cytotoxicity-induced cell proliferation (NOAEL at 1 ppm) is a key mechanism in development of nasal cancer. However, the linear unit risk approach that is based on conservative (“worst-case”) considerations is also used for risk characterization of formaldehyde exposures. Lymphohematopoietic malignancies are not observed consistently in animal studies and if caused by formaldehyde in humans, they are high-dose phenomenons with non-linear exposure–response relationships. Apparently, these diseases are not reported in epidemiological studies at peak exposures below 2 ppm and average exposures below 0.5 ppm. At the similar airborne exposure levels in rodents, the nasal cancer effect is much more prominent than lymphohematopoietic malignancies. Thus, prevention of nasal cancer is considered to prevent lymphohematopoietic malignancies. Departing from the rat studies, the guideline value of the WHO (Air quality guidelines for Europe, 2nd edn. World Health Organization, Regional Office for Europe, Copenhagen, pp 87–91, 2000), 0.08 ppm (0.1 mg m−3) formaldehyde, is considered preventive of carcinogenic effects in compliance with epidemiological findings.

153 citations

Journal ArticleDOI
TL;DR: In this paper, the design, fabrication, and characterization of high-temperature silicon on insulator (SOI) microhotplates employing tungsten resistive heaters is described.
Abstract: This paper is concerned with the design, fabrication, and characterization of novel high-temperature silicon on insulator (SOI) microhotplates employing tungsten resistive heaters. Tungsten has a high operating temperature and good mechanical strength and is used as an interconnect in high temperature SOI-CMOS processes. These devices have been fabricated using a commercial SOI-CMOS process followed by a deep reactive ion etching (DRIE) back-etch step, offering low cost and circuit integration. In this paper, we report on the design of microhotplates with different diameters (560 and 300 mum) together with 3-D electrothermal simulation in ANSYS, electrothermal characterization, and analytical analysis. Results show that these devices can operate at high temperatures (600degC ) well beyond the typical junction temperatures of high temperature SOI ICs (225degC), have ultralow dc power consumption (12 mW at 600degC), fast transient time (as low as 2-ms rise time to 600degC), good thermal stability, and, more importantly, a high reproducibility both within a wafer and from wafer to wafer. We also report initial tests on the long-term stability of the tungsten heaters. We believe that this type of SOI microhotplate could be exploited commercially in fully integrated microcalorimetric or resistive gas sensors.

151 citations


"Fabrication of Microsensor for Dete..." refers background in this paper

  • ...Over the past few decades, various metals and nonmetals, such as platinum [14], gold [15], polysilicon [16], molybdenum [17], nichrome [18], and tungsten [19], are being used as a microheater material for the production of metal oxide gas sensors and are fabricated using conventional lithographybased microfabrication techniques....

    [...]

Journal ArticleDOI
TL;DR: In this article, the authors present a complete thermomechanical study of a micromachined gas sensor substrate, combining coupled electrothermomechanically three-dimensional finite element modelling simulations with electrical, infrared thermography and interferometric microscopy experimental measurements.
Abstract: In this paper, we present a complete thermomechanical study of a micromachined gas sensor substrate. The work has been carried out combining coupled electrothermomechanical three-dimensional finite element modelling simulations with electrical, infrared thermography and interferometric microscopy experimental measurements. The performances predicted by simulations, such as the power consumption (heating efficiency in air of 5.7 °C mW−1), the time response (19 ms), the membrane deflection during operation and the preferential failure sites in the micromachined substrate have been confirmed by experience. Their good agreement validates the model, and allows us to consider the adaptability of this design as a micromachined substrate for integrated gas sensors.

120 citations


"Fabrication of Microsensor for Dete..." refers background in this paper

  • ...Over the past few decades, various metals and nonmetals, such as platinum [14], gold [15], polysilicon [16], molybdenum [17], nichrome [18], and tungsten [19], are being used as a microheater material for the production of metal oxide gas sensors and are fabricated using conventional lithographybased microfabrication techniques....

    [...]