scholarly journals Micro/Nano Gas Sensors: A New Strategy Towards In-Situ Wafer-Level Fabrication of High-Performance Gas Sensing Chips

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Lei Xu ◽  
Zhengfei Dai ◽  
Guotao Duan ◽  
Lianfeng Guo ◽  
Yi Wang ◽  
...  
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Wafer Level ◽  
New Strategy

scholarly journals On-chip assembly of 3D graphene-based aerogels for chemiresistive gas sensing

2020 ◽  
Vol 56 (3) ◽  
pp. 450-453 ◽  
Author(s):  
Gaofeng Shao ◽  
Oleksandr Ovsianytskyi ◽  
Maged F. Bekheet ◽  
Aleksander Gurlo
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
3D Graphene ◽  
On Chip

The first demonstration of the in situ assembly of 3D graphene-based aerogels on a chip as high performance gas sensors towards trace NO2.

scholarly journals Optimization of a Low-Power Chemoresistive Gas Sensor: Predictive Thermal Modelling and Mechanical Failure Analysis

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 783 ◽  
Author(s):  
Andrea Gaiardo ◽  
David Novel ◽  
Elia Scattolo ◽  
Michele Crivellari ◽  
Antonino Picciotto ◽  
...  
Keyword(s):  
Low Power ◽  
Failure Analysis ◽  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Mechanical Failure ◽  
Sensing Applications ◽  
Theoretical Approaches ◽  
Sensing Material ◽  
Silicon Bulk

The substrate plays a key role in chemoresistive gas sensors. It acts as mechanical support for the sensing material, hosts the heating element and, also, aids the sensing material in signal transduction. In recent years, a significant improvement in the substrate production process has been achieved, thanks to the advances in micro- and nanofabrication for micro-electro-mechanical system (MEMS) technologies. In addition, the use of innovative materials and smaller low-power consumption silicon microheaters led to the development of high-performance gas sensors. Various heater layouts were investigated to optimize the temperature distribution on the membrane, and a suspended membrane configuration was exploited to avoid heat loss by conduction through the silicon bulk. However, there is a lack of comprehensive studies focused on predictive models for the optimization of the thermal and mechanical properties of a microheater. In this work, three microheater layouts in three membrane sizes were developed using the microfabrication process. The performance of these devices was evaluated to predict their thermal and mechanical behaviors by using both experimental and theoretical approaches. Finally, a statistical method was employed to cross-correlate the thermal predictive model and the mechanical failure analysis, aiming at microheater design optimization for gas-sensing applications.

scholarly journals Enhancing Formaldehyde Selectivity of SnO2 Gas Sensors with the ZSM-5 Modified Layers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3947
Author(s):  
Wei Wang ◽  
Qinyi Zhang ◽  
Ruonan Lv ◽  
Dong Wu ◽  
Shunping Zhang
Keyword(s):  
Gas Sensors ◽  
Indoor Air ◽  
High Performance ◽  
Screen Printing ◽  
Gas Sensing ◽  
Oxide Semiconductors ◽  
Screen Printing Method ◽  
Gas Sensing Properties ◽  
Zeolite Films ◽  
Insufficient Knowledge

High performance formaldehyde gas sensors are widely needed for indoor air quality monitoring. A modified layer of zeolite on the surface of metal oxide semiconductors results in selectivity improvement to formaldehyde as gas sensors. However, there is insufficient knowledge on how the thickness of the zeolite layer affects the gas sensing properties. In this paper, ZSM-5 zeolite films were coated on the surface of the SnO2 gas sensors by the screen printing method. The thickness of ZSM-5 zeolite films was controlled by adjusting the numbers of screen printing layers. The influence of ZSM-5 film thickness on the performance of ZSM-5/SnO2 gas sensors was studied. The results showed that the ZSM-5/SnO2 gas sensors with a thickness of 19.5 μm greatly improved the selectivity to formaldehyde, and reduced the response to ethanol, acetone and benzene at 350 °C. The mechanism of the selectivity improvement to formaldehyde of the sensors was discussed.

scholarly journals Oxygen-Deficient Stannic Oxide/Graphene for Ultrahigh-Performance Supercapacitors and Gas Sensors

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 372
Author(s):  
Liyang Lin ◽  
Susu Chen ◽  
Tao Deng ◽  
Wen Zeng
Keyword(s):  
Energy Storage ◽  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Synthesis Method ◽  
Rate Capability ◽  
Stannic Oxide ◽  
Energy Storage Devices ◽  
Graphene Nanocomposites ◽  
Storage Devices

The metal oxides/graphene nanocomposites have great application prospects in the fields of electrochemical energy storage and gas sensing detection. However, rational synthesis of such materials with good conductivity and electrochemical activity is the topical challenge for high-performance devices. Here, SnO2/graphene nanocomposite is taken as a typical example and develops a universal synthesis method that overcome these challenges and prepares the oxygen-deficient SnO2 hollow nanospheres/graphene (r-SnO2/GN) nanocomposite with excellent performance for supercapacitors and gas sensors. The electrode r-SnO2/GN exhibits specific capacitance of 947.4 F g−1 at a current density of 2 mA cm−2 and of 640.0 F g−1 even at 20 mA cm−2, showing remarkable rate capability. For gas-sensing application, the sensor r-SnO2/GN showed good sensitivity (~13.8 under 500 ppm) and short response/recovering time toward methane gas. These performance features make r-SnO2/GN nanocomposite a promising candidate for high-performance energy storage devices and gas sensors.

Hierarchically designed ZnO nanostructure based high performance gas sensors

RSC Advances ◽  
2014 ◽  
Vol 4 (90) ◽  
pp. 49521-49528 ◽  
Author(s):  
Mohammad R. Alenezi ◽  
T. H. Alzanki ◽  
A. M. Almeshal ◽  
A. S. Alshammari ◽  
M. J. Beliatis ◽  
...  
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
High Surface ◽  
Hierarchical Nanostructures ◽  
Sensing Properties ◽  
Zno Nanostructure ◽  
Gas Sensing Properties

Enhanced gas sensing properties of ZnO were achieved by designing hierarchical nanostructures with high surface-to-volume ratios and more exposed polar facets.

Fabrication of a Carbon Nanotube Gas Sensor Microelectrodes and its Application for Ammonia Detection

2013 ◽  
Vol 431 ◽  
pp. 306-311
Author(s):  
Xiang Tao Ran ◽  
Zhi Wang ◽  
Li Yang
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Structural Parameters ◽  
Low Cost ◽  
Manufacturing Method ◽  
Multi Walled Carbon Nanotubes ◽  
Ammonia Detection ◽  
Low Cost Manufacturing ◽  
Walled Carbon Nanotubes

With the increasing needs for high-performance gas sensors in industrial production, environmental monitoring and so on, the research on gas sensors is becoming more and more important. In this paper, the electric field intensity distribution simulation process of the interdigital microelectrodes (IMEs) is discussed in details to get the proper electrode structural parameters. The IMEs on the ITO surface with a minimum gap of about 4μm are achieved by lithography, which provides a reliable, low-cost manufacturing method. Sensitive components are made of the multi-walled carbon nanotubes modified materials. The gas-sensing property of the sensor is detected for ammonia. The experiment result shows that the performance of the nanomodified sensor is obviously improved.

Effect of Au Doped WO3 Gas Sensors for NO2 Detection

2011 ◽  
Vol 492 ◽  
pp. 308-311 ◽  
Author(s):  
Wu Bin Gao ◽  
Cheng Dong ◽  
Xu Liu ◽  
Yun Han Ling ◽  
Jia Lin Sun
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Point Contact ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Tungsten Filaments ◽  
Gas Response ◽  
Contact Sensors

Gas sensor based on point contact tungsten trioxide (WO3) was prepared by in-situ induction-heating thermal oxidation of tungsten filaments. X-ray diffractometry (XRD) and field emission scanning electron microscopy (FESEM) were employed to analyze the phase and the morphology of the fabricated thin films. The results showed that the WO3films exhibited a monoclinic phase and were composed of hierarchical micro and nano crystals. The NO2(1-8 ppm) sensing properties of the point contact sensors based on Pure and Au-sputtering doped (2.5 at%) WO3films were investigated. The results showed that the gas sensing properties of the Au (2.5 at%) doped WO3sensors were superior to those of the undoped. The obtained point contact WO3sensor exhibited the maximum NO2gas response at 100°C.

scholarly journals Nitrogen Dioxide Gas Sensor Based on Ag-Doped Graphene: A First-Principle Study

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 227
Author(s):  
Qichao Li ◽  
Yamin Liu ◽  
Di Chen ◽  
Jianmin Miao ◽  
Xiao Zhi ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
High Performance ◽  
Density Functional ◽  
Noble Metals ◽  
Gas Sensing ◽  
Mulliken Charge ◽  
Chronic Obstructive ◽  
Doped Graphene ◽  
The Impact

High-performance tracking trace amounts of NO2 with gas sensors could be helpful in protecting human health since high levels of NO2 may increase the risk of developing acute exacerbation of chronic obstructive pulmonary disease. Among various gas sensors, Graphene-based sensors have attracted broad attention due to their sensitivity, particularly with the addition of noble metals (e.g., Ag). Nevertheless, the internal mechanism of improving the gas sensing behavior through doping Ag is still unclear. Herein, the impact of Ag doping on the sensing properties of Graphene-based sensors is systematically analyzed via first principles. Based on the density-functional theory (DFT), the adsorption behavior of specific gases (NO2, NH3, H2O, CO2, CH4, and C2H6) on Ag-doped Graphene (Ag–Gr) is calculated and compared. It is found that NO2 shows the strongest interaction and largest Mulliken charge transfer to Ag–Gr among these studied gases, which may directly result in the highest sensitivity toward NO2 for the Ag–Gr-based gas sensor.

Formation of Highly Porous Gas-sensing Films by In-situ Thermophoretic Deposition of Nanoparticles from Aerosol Phase

2006 ◽  
Vol 915 ◽  
Author(s):  
Thorsten Sahm ◽  
Weizhi Rong ◽  
Nicolae Barsan ◽  
Lutz Mädler ◽  
Sheldon K. Friedlander ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Tin Dioxide ◽  
Gas Sensing ◽  
High Sensitivity ◽  
High Catalytic Activity ◽  
Flame Spray ◽  
Ceramic Substrates ◽  
Pd Doping ◽  
Sensor Signals

AbstractGas sensors based on tin dioxide nanoparticles show high sensitivity to reducing and oxidizing gases. Dry aerosol synthesis applying the flame spray pyrolysis was used for manufacture and directly (in-situ) deposit nanoparticles on sensor substrates. For the first time this technique has been used to synthesize a combination of two stacked porous layers for gas sensor fabrication. Compared to state-of-the-art techniques, aerosol technology provides a direct and versatile method to produce homogeneous nanoparticle films. Two different sensing layers were deposited directly on interdigital ceramic substrates. These porous bottom layers consisted either of pure tin dioxide or palladium doped tin dioxide. The top layer was a palladium doped alumina nanoparticle film which served as a chemical filter. The fabricated gas sensors were tested with methane, CO and ethanol. In case of CH4 detection, the pure tin dioxide sensor with the Pd/Al2O3 filter layer showed higher sensor signals and significantly improved analyte selectivity with respect to water vapor compared to single tin dioxide films. At temperatures up to 250°C the Pd-doping of the tin dioxide strongly increased the sensitivity to all gases. At higher temperatures the sensor signal significantly decreased for the Pd/SnO2 sensor with a Pd/Al2O3 filter on top indicating high catalytic activity.

The Investigation of Microstructure Silicon NH3 Gas Sensors Based on Polyaniline Nano-Thin Films

2014 ◽  
Vol 998-999 ◽  
pp. 115-119
Author(s):  
Xiao Ying Xu ◽  
Hui Ling Tai ◽  
Chun Hua Liu ◽  
Guang Zhong Xie ◽  
Xiao Song Du
Keyword(s):  
Thin Films ◽  
Gas Sensors ◽  
Self Assembly ◽  
Gas Sensing ◽  
Sem Images ◽  
Interdigital Electrodes ◽  
Gas Sensing Properties ◽  
Response And Recovery

Polyaniline (PANI) nano-thin films were deposited on a novel microstructure silicon (MSS) substrate via in-situ self-assembly approach for NH3gas-sensing. The MSS was prepared by alkaline etching process, and gold interdigital electrodes were formed on the MSS surface by vacuum evaporation. The characterization of the MSS and PANI nanothin film were investigated by scanning electron microscope (SEM) and UV-Vis absorption spectroscopy. SEM images showed that the MSS exhibited an orderly uniform hemisphere array structure, and the MSS surface was covered by a compact PANI thin film which consists of PANI nanoparticles and PANI nanofibers. The gas-sensing properties of the sensor were examined at room temperature. The results revealed that the sensor exhibited a good response and recovery characteristics to NH3.

Sign in / Sign up

Export Citation Format

Share Document