| 1. |
|
|
| 2. |
- Andersson, Mike, 1977-, et al.
(author)
-
Detecting non-hydrogen containing species with field effect devices
- 2008
-
In: IEEE Sensors,2008. - : IEEE. - 9781424425815 - 9781424425808 ; , s. 1320-1323
-
Conference paper (peer-reviewed)abstract
- An investigation of the influence and role of oxygen in the detection of non-hydrogen containing substances with Pt/SiO2/SiC based MOS field effect sensors, employing new model systems, has been carried out. With the use of a novel intermediate layer, by which the direct influence of hydrogen on the sensor response can be markedly reduced, the part of the sensor response which is not directly related to hydrogen (which to a small extent is always present in any gas mixture) could be resolved. The Pt/SiO2 NO reduction/oxidation model system has also been studied from a sensor perspective and the results compared to spectroscopic and mass spectrometry studies of the surface reactions from the field of catalysis. The results support the hypothesis from earlier work that the removal of oxygen from the sensor surface (e.g. by oxidation reactions with CO or NO) to a certain extent directly is involved in the detection of non-hydrogen containing species.
|
|
| 3. |
|
|
| 4. |
- Andersson, Mike, 1977-, et al.
(author)
-
In situ DRIFT study of the CO response mechanism of MISFET sensors using Pt/SiO2 model sensor
- 2008
-
In: Proceedings of IEEE Sensors. - : IEEE. - 9781424425815 - 9781424425808 ; , s. 1309-1312
-
Conference paper (peer-reviewed)abstract
- The temperature dependence of the sensor response towards CO of SiC-FET sensors has been studied by combining in situ DRIFT spectroscopy and sensor response measurements. The DRIFT spectroscopy studies have been performed on a model sensor representing the top layer of a SiC-FET sensor with porous Pt gate. Adsorbates on the model sensor have been studied at varying temperatures and gas concentrations, and correlated to sensor response measurements at similar experimental conditions. The results show that the temperature dependence partly can be correlated to the CO coverage of the surface. The switching point of the sensor response, observed at different temperatures depending on the CO and oxygen concentrations is well in accordance with the kinetics of the CO oxidation reaction.
|
|
| 5. |
- Andersson, Mike, 1977-, et al.
(author)
-
Recent progress in silicon carbide field effect gas sensors
- 2020. - 2
-
In: Semiconductor gas sensors. - Oxford : Woodhead Publishing Limited. - 9780081025598 ; , s. 309-346
-
Book chapter (peer-reviewed)abstract
- The introduction of silicon carbide as the semiconductor in gas-sensitive field effect devices has disruptively improved this sensor platform extending the operation temperature to more than 600 °C with an increased number of detectable gases. Here, we review recent progress in research and applications, starting with transducer and detection mechanisms, presenting new material combinations as sensing layers for improved selectivity and detection limits down to subparts per billion. We describe how temperature cycled operation combined with advanced data evaluation enables one sensor to act as a sensor array thereby vastly improving selectivity. Field tests require advanced packaging, which is described, and examples of possible applications like selective detection of ammonia for urea injection control in diesel exhausts and toxic volatile organic compounds for indoor air quality monitoring and control are given.
|
|
| 6. |
- Bastuck, Manuel, et al.
(author)
-
Low-cost chemical gas sensors for selective formaldehyde quantification at ppb-level in field tests
- 2017
-
Conference paper (peer-reviewed)abstract
- Data from a silicon carbide based field-effect transistor were recorded over a period of nine days in a ventilated school room. For enhanced sensitivity and selectivity especially to formaldehyde, porous iridium on pulsed laser deposited tungsten trioxide was used as sensitive layer, in combination with temperature cycled operation and subsequent multivariate data processing techniques. The sensor signal was compared to reference measurements for formaldehyde concentration, CO2 concentration, temperature, and relative humidity. The results show a distinct pattern for the reference formaldehyde concentration, arising from the day/night cycle. Taking this into account, the projections of both principal component analysis and partial least squares regression lead to almost the same result concerning correlation to the reference. The sensor shows cross-sensitivity to an unidentified component of human activity, presumably breath, and, possibly, to other compounds appearing together with formaldehyde in indoor air. Nevertheless, the sensor is able to detect and partially quantify formaldehyde below 40 ppb with a correlation to the reference of 0.48 and negligible interference from ambient temperature or relative humidity.
|
|
| 7. |
- Bastuck, Manuel, et al.
(author)
-
UV-assisted gate bias cycling in gas-sensitive field-effect transistors
- 2018
-
In: Proceedings. - Basel Switzerland : MDPI. - 2504-3900. ; 2:13
-
Journal article (peer-reviewed)abstract
- Static and dynamic responses of a silicon carbide field-effect transistor gas sensor have been investigated at two different gate biases in several test gases. Especially the dynamic effects are gas dependent and can be used for gas identification. The addition of ultraviolet light reduces internal electrical relaxation effects, but also introduces new, temperature-dependent effects.
|
|
| 8. |
- Basu, P. K., et al.
(author)
-
Schottky Junction Methane Sensors using Electrochmically Grown Nanocrystalline-Nanoporous ZnO Thin Films
- 2009
-
In: Journal of Sensors. - : Hindawi Publishing Corporation. - 1687-725X .- 1687-7268. ; 2009:790476, s. 1-9
-
Journal article (other academic/artistic)abstract
- Nanocrystalline-nanoporous ZnO thin films were prepared by an electrochemical anodization method, and the films were tested as methane sensors. It was found that Pd-Ag catalytic contacts showed better sensing performance compared to other noble metal contacts like Pt and Rh. The methane sensing temperature could be reduced to as low as 100°C by sensitizing nanocrystalline ZnO thin films with Pd, deposited by chemical method. The sensing mechanism has been discussed briefly.
|
|
| 9. |
|
|
| 10. |
- Buchholt, Kristina, 1978-, et al.
(author)
-
Electrochemically Synthesised Pd- and Au-nanoparticles as sensing layers in NOx-sensitive field effect devices
- 2008
-
In: Smart Sensors and Sensing Technology. - Berlin, Heidelberg : Springer. - 9783540795896 - 9783540795902 ; , s. 63-75
-
Conference paper (other academic/artistic)abstract
- An environmental pollutant of great concern is NOx (nitrogen monoxide and nitrogen dioxide). Here we report the utilisation of electrochemically synthesised gold and palladium nanoparticles as catalytically active gate material on gas sensitive field effect sensor devices. The synthesised nanoparticles have been characterised by TEM and XPS, and the morphology of the thermally treated nanostructured sensing layers has been investigated using SEM and XPS. Measurements on the gas response of the palladium as well as the gold nanoparticle sensors towards a number of analytes found in automotive gas exhausts were performed and their response patterns were compared. The initial gas response measurements show interesting sensing properties for both the gold and the palladium nanoparticle sensors towards NOx detection.
|
|
| 11. |
|
|
| 12. |
- Di Natale, Corrado, et al.
(author)
-
Investigation of the selectivity properties of metalloporphyrines self-assembled-monolayers on QMB and FET transducers
- 2006
-
In: Proc Eurosensors XX.
-
Conference paper (peer-reviewed)abstract
- Progresses of synthetic chemistry methodologies have allowed the preparation of a great variety of artificial receptors that are particularly appealing for chemical sensor development. In this paper, we investigate and compare the properties of gas sensors based on two types of devices, quartz microbalances (QMBs) and field effect transistors (FETs), which give the means to exploit the molecular recognition events occurring in non-conductive sensing layers formed by a thiol-modified cobalt tetraphenylporphyrin (CoTPPSH). Since QMB is sensitive to mass and FET is sensitive to electric dipoles, the resulting sensors are expected to exhibit different sensitivities and selectivities, although both based on the same sensing layer. In particular we show that the high sensitivity of CoTPPSH-coated FETs towards CO and NO is a consequence of the significant CoTPPSH electric dipole change after the gas coordination to the metal centre.
|
|
| 13. |
- Erdtman, Edvin, 1981-, et al.
(author)
-
Simulations of the thermodynamics and kinetics of NH3 at the RuO2 (110) surface
- 2017
-
In: Surface Science. - : Elsevier. - 0039-6028 .- 1879-2758. ; 656, s. 77-85
-
Journal article (peer-reviewed)abstract
- Ruthenium(IV)oxide (RuO2) is a material used for various purposes. It acts as a catalytic agent in several reactions, for example oxidation of carbon monoxide. Furthermore, it is used as gate material in gas sensors. In this work theoretical and computational studies were made on adsorbed molecules on RuO2 (110) surface, in order to follow the chemistry on the molecular level. Density functional theory calculations of the reactions on the surface have been performed. The calculated reaction and activation energies have been used as input for thermodynamic and kinetics calculations. A surface phase diagram was calculated, presenting the equilibrium composition of the surface at different temperature and gas compositions. The kinetics results are in line with the experimental studies of gas sensors, where water has been produced on the surface, and hydrogen is found at the surface which is responsible for the sensor response.
|
|
| 14. |
|
|
| 15. |
- Hasegawa, Yuki, et al.
(author)
-
Development of Agriculture Support System Using Plant Bioelectric Potential Responses and Gas Sensor
- 2017
-
In: International Journal of Food and Biosystems Engineering. - 2408-0675. ; 5:1, s. 44-51
-
Journal article (peer-reviewed)abstract
- In this study,we focus on the plant bioelectric potential response as a low-cost and a high sensitivity evaluation technique of plant physiological activities for an agriculture support system. We developed a cultivation light intensity control system using bioelectric potential response. This system contributes to improvement of the cultivation environment and provides energy saving effect.In addition, we introduced a field effect transistor based on silicon carbide (SiC-FET)gas sensor and evaluated the characteristics of the sensor by changing several parameters. The results showed that iridium gated SiC-FET sensor has high sensitivity to ethylene,and the highest response is achieved at 200 ◦C. We aim at the development of an agriculture support system, which combines the plant bioelectrical potential and the SiC-FET gas sensor response.
|
|
| 16. |
|
|
| 17. |
- Ieva, Eliana, 1979-, et al.
(author)
-
Gold Nanoparticle Sensors For Environmental Pollutant Monitoring
- 2007
-
In: Proceedings of the 2007 2nd IEEE International Workshop on Advances in Sensors and Interfaces, June 26-27, 2007 Bari, Italy. - : IEEE. - 9781424412457 - 9781424412457 ; , s. 1-4
-
Conference paper (other academic/artistic)abstract
- Gold nanoparticles (Au-NPs) have been synthesised using a sacrificial anode electrolysis in the presence of tetra-alkyl-ammonium halides, employed as cationic stabilizers. Catalytic NPs have been then deposited on top of Field Effect (FE) gas sensing devices and subjected to mild annealing procedures. Transmission Electron Microscopy (TEM) shows that the NP average core diameter is around 5 nm. X-Ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM) have been applied to the surface characterization of the annealed NP films used as active sensing layers. Morphological and spectroscopic results demonstrate that the annealed inorganic nano-clusters are finely dispersed and maintain a metallic oxidation state. Au-NPs can be proficiently employed as gate material in Si-Field Effect Gas Sensors. Preliminary results show interesting selectivity and sensitivity sensing features towards NOx detection.
|
|
| 18. |
|
|
| 19. |
- Khranovskyy, Volodymyr, 1979-, et al.
(author)
-
Oxygen absorption effect on the sensitivity and material stability of ZnO nanostructured films
- 2008
-
In: Proceedings of IEEE Sensors. - : IEEE. - 9781424425815 - 9781424425808 ; , s. 874-877
-
Conference paper (peer-reviewed)abstract
- In this work the effect of ambient influence on the electrical conductivity of ZnO films has been studied. Nanostructured ZnO films (undoped and Ga, Co, Mn doped) were exposed to oxygen (1-80 vol.%) at temperature range 300-500degC. A dominant effect of ambient influence via oxygen absorption was observed: the intensity of conductivity decrease was found to be proportional with temperature and tends to saturation with time. After oxygen saturation the reversible effect of oxygen adsorption became dominant and contributed to the films conductivity. Oxygen exposed undoped ZnO films revealed high sensitivity for oxygen content change in the ambience, therefore they have been further processed for gas sensor fabrication.
|
|
| 20. |
- Kilpijärvi, Joni
(author)
-
RF-microwave sensor development for cell and human in vitro and ex vivo monitoring
- 2021
-
Doctoral thesis (other academic/artistic)abstract
- In this research new RF/microwave-based sensor solutions were developed for the monitoring of biological cells and human beings to obtain a better understanding of their activity or state in a quick, cheap, easy and continuous way. The effect of different substances on cell behaviour can be monitored by measuring the electrical environment where changes are observed as cells react to a stimulus. The starting point of the study was a microchip with a capacitance measurement system integrated into the culturing chamber, enabling the monitoring of cell proliferation or death. The main challenge of the study was the correct interpretation of the received signals and the combination of “dry” electronics and “wet” biology, which is a difficult issue in terms of reliability and durability of the system. For this purpose, a low temperature co-fired ceramic package was developed which could withstand cell culture conditions and which did not interfere with the cell activity. A 1.1 MHz shift in resonance frequency of the system could clearly be measured, where the shift depended on the number of cells. Another topic of the research concentrated on a microwave sensor that can be utilized in the examination and analysis of fluid samples collected from the body which provide information about a person’s health status. A microwave sensor was developed, which was tested with liquid samples. Microfluidics were also integrated into the system which allowed the use of very small sample volumes and improved the usability of the device. The challenge of the work was to build the system so that the parts were integrated seamlessly without interfering with each other. The sensor concept was tested successfully using typical concentrations of NaCl found in human blood plasma i.e. 125 to 155 mmol/mol of water. The third topic of the thesis was aiming for a microwave sensor that enables real-time measurement of body fluid balance directly from the skin. The operation of the developed microwave sensor was based on a resonator whose resonance frequency reacted to the electrical properties of materials in its proximity, in this case the water content of the skin and its changes. The function of the sensor was tested with artificial skin, made in the laboratory, which corresponded to the properties of real skin. The observed changes in resonance frequency was +370 MHz and -220 MHz for dehydrated and hydrated skin compared to normal skin, thus providing a wide frequency range for detection of the status of the skin.
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
- Lloyd Spetz, Anita, 1951-, et al.
(author)
-
Gas sensors in Synthesis, Properties and Applications of Oxide Nanomaterials
- 2007. - 1
-
In: Synthesis, properties and applications of oxide nanomaterials. - New Jersey, USA : John Wiley & Sons. - 047172405X - 9780471724056 ; , s. 411-450
-
Book chapter (other academic/artistic)abstract
- Current oxide nanomaterials knowledge to draw from and build on Synthesis, Properties, and Applications of Oxide Nanomaterials summarizes the existing knowledge in oxide-based materials research. It gives researchers one comprehensive resource that consolidates general theoretical knowledge alongside practical applications. Organized by topic for easy access, this reference: Covers the fundamental science, synthesis, characterization, physicochemical properties, and applications of oxide nanomaterials Explains the fundamental aspects (quantum-mechanical and thermodynamic) that determine the behavior and growth mode of nanostructured oxides Examines synthetic procedures using top-down and bottom-up fabrication technologies involving liquid-solid or gas-solid transformations Discusses the sophisticated experimental techniques and state-of-the-art theory used to characterize the structural and electronic properties of nanostructured oxides Describes applications such as sorbents, sensors, ceramic materials, electrochemical and photochemical devices, and catalysts for reducing environmental pollution, transforming hydrocarbons, and producing hydrogen With its combination of theory and real-world applications plus extensive bibliographic references, Synthesis, Properties, and Applications of Oxide Nanomaterials consolidates a wealth of current, complex information in one volume for practicing chemists, physicists, and materials scientists, and for engineers and researchers in government, industry, and academia. It's also an outstanding reference for graduate students in chemistry, chemical engineering, physics, and materials science.
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
- Martinelle, E, et al.
(author)
-
FET Transduction of Electric Dipole Changes in Organic Layers
- 2007
-
In: TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference. - : IEEE. - 1424408423 - 1424408415 ; , s. 1895-1898
-
Conference paper (peer-reviewed)abstract
- Modern chemistry makes possibile the production of artificial receptors endowed with interaction sites specific towards selected analytes. To fabricate chemical sensors a transducer able to preserve the selectivity of such sensing layers is requested. We demonstrate the Field Effect Transistors (FET) coated by metalloporphyrins emphasizes the coordination of analytes with the sensing molecules with respect to the weakest forces that tend to cancel the selectivity. Molecular simulations show that coordination of gases such as carbon monoxide and nitric oxide greatly change the porphyrin electric dipole both in magnitude and direction inducing a large FET signal shift.
|
|
| 27. |
|
|
| 28. |
|
|
| 29. |
- Torsi, Luisa, et al.
(author)
-
Organic thin-film transistors for inorganic substance monitoring
- 2009. - 1
-
In: Organic electronics in Sensors and Biotechnology. - New York : McGraw-Hill Companies Inc. - 9780071596756 ; , s. 51-91
-
Book chapter (other academic/artistic)abstract
- Develop high-performance, field-deployable organic semiconductor-based biological, chemical, and physical sensor arrays using the comprehensive information contained in this definitive volume. Organic Electronics in Sensors and Biotechnology presents state-of-the-art technology alongside real-world applications and ongoing R & D.Learn about light, temperature, and pressure monitors, integrated flexible pyroelectric sensors, sensing of organic and inorganic compounds, and design of compact photoluminescent sensors. You will also get full details on organic lasers, organic electronics in memory elements, disease and pathogen detection, and conjugated polymers for advancing cellular biology.Monitor organic and inorganic compounds with OFETsCharacterize organic materials using impedance spectroscopyWork with organic LEDs, photodetectors, and photovoltaic cellsForm flexible pyroelectric sensors integrated with OFETsBuild PL-based chemical and biological sensing modules and arraysDesign organic semiconductor lasers and memory elementsUse luminescent conjugated polymers as optical biosensorsDeploy polymer-based switches and ion pumps at the microfluidic level
|
|
| 30. |
- Yakimova, Rositsa, 1942-, et al.
(author)
-
Novel material concepts of transducers for chemical and biosensors
- 2007
-
In: Biosensors & bioelectronics. - : Elsevier BV. - 0956-5663 .- 1873-4235. ; 22:12, s. 2780-2785
-
Journal article (peer-reviewed)abstract
- The objectives of this work are to contribute to the knowledge about physical and chemical properties of WBG semiconductors, such as ZnO and GaN towards development of advanced bio- and chemical sensors. For the semiconductors, growth techniques typically yielding single crystal material are applied. Thin epitaxial quality films of ZnO and GaN are fabricated on SiC or sapphire substrates. An emphasis is given to ZnO due to the interesting combination of the semiconductor and oxide properties. Surface bio-functionalization of ZnO is performed by APTES, MPA or MP-TMS molecules. We have compared some of the results to (hydroxylated) GaN surfaces functionalized by MP-TMS. The covalent attachment of the self-assembled biomolecular layers has been proven by XPS analysis. For complementary electrical characterization impedance spectroscopy measurements were performed. The results are intended to serve the realization of bioelectronic transducer devices based on SiC or GaN transistors with a ZnO gate layer. To take advantage of the catalytic properties of ZnO, initial prototypes of chemical sensors for gas sensing are processed on ZnO deposited either on SiC or on sapphire and they are further tested for the response to reducing or oxidizing gas ambient. The sensor devices show sensitivity to oxygen in the surface resistivity mode while a Pt Schottky contact ZnO/SiC device responds to reducing gases. These results are compared to published results on Pt/GaN Schottky diodes. © 2007 Elsevier B.V. All rights reserved.
|
|
| 31. |
- Yakimova, Rositsa, 1942-, et al.
(author)
-
Surface functionalization and biomedical applications based on SiC
- 2007
-
In: Journal of Physics D. - 0022-3727 .- 1361-6463. ; 40:20, s. 6435-6442
-
Journal article (peer-reviewed)abstract
- The search for materials and systems, capable of operating long term under physiological conditions, has been a strategy for many research groups during the past years. Silicon carbide (SiC) is a material, which can meet the demands due to its high biocompatibility, high inertness to biological tissues and to aggressive environment, and the possibility to make all types of electronic devices. This paper reviews progress in biomedical and biosensor related research on SiC. For example, less biofouling and platelet aggregation when exposed to blood is taken advantage of in a variety of medical implantable materials while the robust semiconducting properties can be explored in surface functionalized bioelectronic devices. © 2007 IOP Publishing Ltd.
|
|
