scholarly journals New approaches for improving selectivity and sensitivity of resistive gas sensors: a review

Sensor Review ◽  
2015 ◽  
Vol 35 (4) ◽  
pp. 340-347 ◽  
Author(s):  
Janusz Marek Smulko ◽  
Maciej Trawka ◽  
Claes Goran Granqvist ◽  
Radu Ionescu ◽  
Fatima Annanouch ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Experimental Studies ◽  
Low Frequency ◽  
Gas Detection ◽  
Temperature Modulation ◽  
Content Type ◽  
Practical Applications ◽  
Noise Data ◽  
Resistive Gas Sensors

Purpose – This paper aims to present the methods of improving selectivity and sensitivity of resistance gas sensors. Design/methodology/approach – This paper compares various methods of improving gas sensing by temperature modulation, UV irradiation or fluctuation-enhanced sensing. The authors analyze low-frequency resistance fluctuations in commercial Taguchi gas sensors and the recently developed tungsten trioxide (WO3) gas-sensing layers, exhibiting a photo-catalytic effect. Findings – The efficiency of using low-frequency fluctuations to improve gas detection selectivity and sensitivity was confirmed by numerous experimental studies in commercial and prototype gas sensors. Research limitations/implications – A more advanced measurement setup is required to record noise data but it will reduce the number of gas sensors necessary for identifying the investigated gas mixtures. Practical implications – Fluctuation-enhanced sensing can reduce the energy consumption of gas detection systems and assures better detection results. Originality/value – A thorough comparison of various gas sensing methods in resistance gas sensors is presented and supported by exemplary practical applications.

A Strategy to Improve O2 Gas Response of La-SnO2 Nanofibers Based Sensor through Temperature Modulation

2019 ◽  
Vol 944 ◽  
pp. 657-665
Author(s):  
Ya Xiong ◽  
Hui Li ◽  
Tian Chao Guo ◽  
Qing Zhong Xue
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Operation Mode ◽  
Temperature Modulation ◽  
Oxide Semiconductors ◽  
Oxygen Ions ◽  
Isothermal Test ◽  
Sensor Temperature ◽  
Heating Energy Consumption ◽  
Gas Response

Generally sensing mechanisms of gas sensors based on metal-oxide semiconductors greatly depend on temperature, suggesting temperature modulation can be applied as a vital method to effectively enhance the sensor response. In this paper, we reported a strategy of quick-cooling operating temperature mode in the course of gas sensing process to elevate the O2 gas response while maintaining low heating energy consumption. La-SnO2 nanofibers synthesized by electrospinning were chosen as gas sensing materials. The O2 gas responses by employing quick-cooling operation mode are significantly improved compared with those obtained by traditional isothermal test. The improved O2 response is contributed to a higher coverage of negatively charged oxygen ions as a result of quick cooling. Our research offers a facile route to detect gas at low temperature with high response. More importantly, the strategy demonstrated here could also be extended to other gas sensor as long as its gas response is related to the sensor temperature.

scholarly journals Hollow-Core Photonic Crystal Fiber Gas Sensing

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2996 ◽  
Author(s):  
Ruowei Yu ◽  
Yuxing Chen ◽  
Lingling Shui ◽  
Limin Xiao
Keyword(s):  
Photonic Crystal ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Deep Understanding ◽  
Industrial Applications ◽  
Hollow Core ◽  
Fundamental Limits ◽  
Practical Applications ◽  
Wide Range ◽  
Crystal Fibers

Fiber gas sensing techniques have been applied for a wide range of industrial applications. In this paper, the basic fiber gas sensing principles and the development of different fibers have been introduced. In various specialty fibers, hollow-core photonic crystal fibers (HC-PCFs) can overcome the fundamental limits of solid fibers and have attracted intense interest recently. Here, we focus on the review of HC-PCF gas sensing, including the light-guiding mechanisms of HC-PCFs, various sensing configurations, microfabrication approaches, and recent research advances including the mid-infrared gas sensors via hollow core anti-resonant fibers. This review gives a detailed and deep understanding of HC-PCF gas sensors and will promote more practical applications of HC-PCFs in the near future.

Wireless passive surface acoustic wave (SAW) technology in gas sensing

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yong Pan ◽  
Qin Molin ◽  
Tengxiao Guo ◽  
Lin Zhang ◽  
Bingqing Cao ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Gas Sensor ◽  
Surface Acoustic Wave ◽  
Potential Application ◽  
Gas Sensing ◽  
Development Trend ◽  
Gas Detection ◽  
Content Type ◽  
Research Status ◽  
Saw Sensor

Purpose This paper aims to give an overview about the state of wireless passive surface acoustic wave (SAW) gas sensor used in the detection of chemical vapor. It also discusses a variety of different architectures including delay line and array sensor for gas detection, and it is considered that this technology has a good application prospect. Design/methodology/approach The authors state the most of the wireless passive SAW methods used in gas sensing, such as CO2, CO, CH4, C2H4, NH3, NO2, et al., the sensor principles, design procedures and technological issues are discussed in detail; their advantages and disadvantages are also summarized. In conclusion, it gives a prospect of wireless passive SAW sensor applications and proposes the future research field might lie in the studying of many kinds of harmful gases. Findings In this paper, the authors will try to cover most of the important methods used in gas sensing and their recent developments. Although wireless passive SAW sensors have been used successfully in harsh environments for the monitoring of temperature or pressure, the using in chemical gases are seldom reported. This review paper gives a survey of the present state of wireless passive SAW sensor in gas detection and suggests new and exciting perspectives of wireless passive SAW gas sensor technology. Research limitations/implications The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted. Originality/value The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted.

Enhancement of the gas sensing performance of carbon nanotube networked films based on their electrophoretic functionalization with gold nanoparticles

2015 ◽  
Vol 1786 ◽  
pp. 37-42 ◽  
Author(s):  
E. Dilonardo ◽  
M. Penza ◽  
M. Alvisi ◽  
C. Di Franco ◽  
D. Suriano ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Sensing Applications ◽  
Active Layers ◽  
Resistive Gas Sensors ◽  
Ppm Level ◽  
Fine Tune ◽  
Pollutant Gases ◽  
Higher Sensitivity

ABSTRACTControlled amounts of colloidal Au nanoparticles (NPs), electrochemically pre-synthesized, were directly deposited on MWCNTs sensor devices by electrophoresis. Pristine and Au-functionalized MWCNT networked films were tested as active layers in resistive gas sensors for detection of pollutant gases. Au-modified CNT-chemiresistor demonstrated higher sensitivity to NO2 detecting up to sub-ppm level compared to pristine one. The investigation of the cross-sensitivity towards other pollutant gases revealed the decrease of the sensitivity to NO2 with the increase of Au content, and, on the other side, the increase of that to H2S; therefore the fine tune of the metal loading on CNTs has allowed to control not only the gas sensitivity but also the selectivity towards a specific gaseous analyte. Finally, the sensing properties of Au-decorated CNT sensor seem to be promising in environmental and automotive gas sensing applications, based on low power consumption and moderate operating temperature.

Nanomaterials for gas sensing: a review of recent research

Sensor Review ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Robert Bogue
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
Design Methodology ◽  
Gas Sensing ◽  
Research Effort ◽  
Extensive Literature ◽  
Titanium Dioxide Nanotubes ◽  
Content Type ◽  
Metal Oxide Nanomaterials ◽  
The Subject

Purpose – This paper aims to provide a detailed review of gas sensor research which exploits the properties of nanomaterials and nanostructures. Design/methodology/approach – Following an introduction, this paper discusses developments in gas sensors based on carbon nanotubes, titanium dioxide nanotubes, graphene, nanocrystalline diamond and a range of metal oxide nanomaterials. It concludes with a discussion of this research and its commercial potential and a list of references to the research considered in the main text. Findings – Gas sensors based on a multitude of nanomaterials are the subject of a global research effort which has generated an extensive literature. Prototype devices have been developed which respond to numerous important gases at concentrations which correspond well with industrial requirements. Other critical performance characteristics have been studied extensively and the results suggest commercial prospects for these technologies. Originality/value – This paper provides details of the highly topical field of nanomaterial-based gas sensor research.

Thermal detection mechanism of SiC-Based Resistive Gas Sensors

2006 ◽  
Vol 911 ◽  
Author(s):  
Timothy J. Fawcett ◽  
Meralys Reyes ◽  
Anita Lloyd Spetz ◽  
Stephen E. Saddow ◽  
John T. Wolan
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Thermal Contact ◽  
Detection Mechanism ◽  
First Order ◽  
Sensing Mechanism ◽  
Temperature Detector ◽  
Dc Bias ◽  
Thermal Detection ◽  
Resistive Gas Sensors

AbstractSilicon carbide-based resistive gas sensors from our laboratory have been previously reported to detect hydrogen at concentrations ranging from less than 1% to 100% H2 in Ar and at temperatures ranging from 50°C to 450°C. The gas sensing mechanism for these devices was not well understood, hindering further improvement in this technology. In this report, resistive devices built on a thin 3C-SiC epitaxial layer grown on 150Å thick Si layer wafer bonded to a polycrystalline SiC substrate were studied. The polycrystalline SiC substrate is insulating, allowing the formation of isolated epitaxy resistors on the 3C-SiC layer. The gas sensing devices consisted of rectangular ohmic NiCr contacts with a Au overlayer fabricated on the 3C-SiC surface. Under a constant dc bias, nominally 10V in this study, these sensors demonstrated a decrease in current of up to ~25.4 mA upon the introduction of 100% H2, relative to 100% N2 in the test gas stream. The time constant for this device, estimated as a first-order exponential decay, was ~16-22 sec, with the full response occurring after ~90-120 sec. Upon the introduction of 100% H2 to the sensing environment, the device temperature, as measured by an resistance temperature detector (RTD) in intimate thermal contact with the device, decreased from 400°C to 237°C (ΔT = ~163°C). This large decrease in device temperature was driven by increased heat transfer coefficient of H2 relative to N2. The sensitivity to CH4 in N2, CO2 in N2 and He in Ar was also tested. Sensitivities, defined as the smallest change in concentration, as low as 300 ppm H2 in N2 were achieved with devices operating at 400°C and 10 V dc. Details of the device performance and a model of the sensing mechanism will be discussed.

Gas Sensing Properties of Columnar CeO2 Nanostructures Prepared by Chemical Vapor Deposition

2008 ◽  
Vol 8 (2) ◽  
pp. 1012-1016 ◽  
Author(s):  
Davide Barreca ◽  
Elisabetta Comini ◽  
Alberto Gasparotto ◽  
Chiara Maccato ◽  
Cinzia Maragno ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Sensors ◽  
Vapor Deposition ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Operating Conditions ◽  
Working Temperature ◽  
Gas Sensing Properties ◽  
Resistive Gas Sensors ◽  
Higher Sensitivity

Columnar CeO2 nanostructures are grown on alumina substrates by a template- and catalyst-free Chemical Vapor Deposition (CVD) approach and subsequently tested as resistive gas sensors of CH3COCH3, H2, NO2. The sensor response is stable and reproducible throughout the whole working temperature range (200–500 °C) and directly dependent on the analyte gas and the adopted operating conditions. The higher sensitivity with respect to that displayed by continuous CeO2 thin films demonstrates the potential of fabricating nanostructured sensing devices characterized by improved functional performances.

A review: electrical and gas sensing properties of polyaniline/ferrite nanocomposites

Sensor Review ◽  
2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Thejas Ramakrishnaiah ◽  
Prasanna Gunderi Dhananjaya ◽  
Chaturmukha Vakwadi Sainagesh ◽  
Sathish Reddy ◽  
Swaroop Kumaraswamy ◽  
...  
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Room Temperature ◽  
Gas Sensing ◽  
Cost Effective ◽  
Content Type ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Gas Sensing Properties

Purpose This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of high-performance electrical and gas sensing materials operating at room temperature. Design/methodology/approach PANI/ferrite nanocomposites exhibit good electrical properties with lower dielectric losses. There are numerous reports on PANI and ferrite nanomaterial-based gas sensors which have good sensing response, feasible to operate at room temperature, requires less power and cost-effective. Findings This paper provides an overview of electrical and gas sensing properties of PANI/ferrite nanocomposites having improved selectivity, long-term stability and other sensing performance of sensors at room temperature. Originality/value The main purpose of this review paper is to focus on PANI/ferrite nanocomposite-based gas sensors operating at room temperature.

Nanostructured WO3 based gas sensors: a short review

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Srinivas Rao Sriram ◽  
Saidireddy Parne ◽  
Venkata Satya Chidambara Swamy Vaddadi ◽  
Damodar Edla ◽  
Nagaraju P. ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Synthesis Method ◽  
Short Review ◽  
Future Research ◽  
Synthesis Methods ◽  
Content Type ◽  
Healthy Environment ◽  
Toxic Gases ◽  
Sensing Performance

Purpose This paper aims to focus on the basic principle of WO3 gas sensors to achieve high gas-sensing performance with good stability and repeatability. Metal oxide-based gas sensors are widely used for monitoring toxic gas leakages in the environment, industries and households. For better livelihood and a healthy environment, it is extremely helpful to have sensors with higher accuracy and improved sensing features. Design/methodology/approach In the present review, the authors focus on recent synthesis methods of WO3-based gas sensors to enhance sensing features towards toxic gases. Findings This work has proved that the synthesis method led to provide different morphologies of nanostructured WO3-based material in turn to improve gas sensing performance along with its sensing mechanism. Originality/value In this work, the authors reviewed challenges and possibilities associated with the nanostructured WO3-based gas sensors to trace toxic gases such as ammonia, H2S and NO2 for future research.

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