| 1. |
- Lundström, Ingemar, et al.
(författare)
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Recent developments in field-effect gas sensors
- 1995
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 23:2-3, s. 127-133
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Tidskriftsartikel (refereegranskat)abstract
- Some of the ongoing studies at our laboratory of gas-sensitive field-effect devices with catalytic metal gates are reviewed. More particularly, we discuss the use of such devices in so-called electronic noses due to the possibility of changing the selectivity patterns of the devices by the choice of catalytic metal and operation temperature. Several examples of the application of electronic noses consisting of field-effect devices in combination with metal oxide-based sensors are given. Finally, a summary is given of some remaining scientific problems and studies related to the understanding and development of gas-sensitive field-effect devices.
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| 2. |
- Belov, Ilja, et al.
(författare)
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CFD analysis of packaging and mounting solutions for SiC-based gas sensors in automotive applications
- 2006
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Ingår i: Sensor Letters. - 1546-198X. ; 4:1, s. 29-37
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Tidskriftsartikel (refereegranskat)abstract
- Simulation-based guidelines were developed for designing tube-mounted gas sensors in the exhaust pipes of diesel and petrol engines, taking into account thermal constraints and gas flow conditions. Different block and tube mounting alternatives for SiC-based gas sensors were studied by means of temperature measurements and simulation of steady state heat transfer and gas flow. Design variables included the number of fins in the heat sink mounted on the inlet tube, the inlet construction, the mounting tube orientation, and the micro-heater substrate placement inside the mounting tube. The most preferable tube mounting design was determined with respect to the thermal performance of the sensor structure and with respect to the gas flow parameters, which are important for the sensor's selectivity, sensitivity and response time.
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| 3. |
- Belov, Ilja, et al.
(författare)
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Thermal and flow analysis of SiC-based gas sensors for automotive applications
- 2004
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Ingår i: Proceedings of the 5th International Conference on Thermal and Mechanical Simulation and Experiments in Microelectronics and Microsystems, 2004. - : IEEE. - 0780384202 ; , s. 475-482
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Konferensbidrag (refereegranskat)abstract
- Different block and tube mounting alternatives for SiC-based gas sensors were studied by means of temperature measurements and simulation of heat transfer and gas flow for steady state conditions. The most preferable tube mounting design was determined. Simulation-based guidelines were developed for designing tube-mounted gas sensors in the exhaust pipes of diesel and petrol engines, taking into account thermal constraints and flow conditions.
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| 4. |
- Björkman, Hans, et al.
(författare)
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Political entrepreneurship in action research : learning from two cases
- 2005
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Ingår i: Journal of Organizational Change Management. - : Emerald. - 1758-7816 .- 0953-4814. ; 18:5, s. 399-415
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Tidskriftsartikel (refereegranskat)abstract
- Purpose To discuss political entrepreneurship as a capability to enable durable insider action research projects. Design/methodology/approach The two authors utilize auto‐ethnographic methods in order to evaluate and draw inferences from their own actions as insider action researchers. The paper draws on action research theory and theories on political entrepreneurship. Findings Political entrepreneurship is an important factor behind success or failure in action research projects, but has, despite this, been scarcely discussed in the action research literature. Findings indicate that a political entrepreneurship repertoire consisting of capabilities to find red‐hot issues for one's research, to use the inside of the organization in the research efforts, to use and diffuse the research results, and, finally, to work on the positioning of one's relational platform. Research limitations/implications The study is based upon case studies in two organizations. Its implications may be further developed through studies in a wider array of settings. Practical implications The study provides valuable knowledge for organizations intending to participate in (insider) action research as well as for (insider) action researchers. Originality/value Political entrepreneurship in action research is scarcely discussed in action research theory and hence the paper addresses an important research gap. Moreover, the presented implications have a certain practical value for organizations and researchers.
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| 5. |
- Briand, D., et al.
(författare)
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Low-power micromachined MOSFET gas sensor
- 2000
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Ingår i: Journal of microelectromechanical systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 9:3, s. 303-308
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the design, fabrication, and characterization of the first low-power consumption MOSFET gas sensor. The novel MOSFET array gas sensor has been fabricated using anisotropic bulk silicon micromachining. A heating resistor, a diode used as temperature sensor, and four MOSFETs are located in a silicon island suspended by a dielectric membrane. The membrane has a low thermal conductivity coefficient and, therefore, thermally isolates the electronic components from the chip frame. This low thermal mass device allows the reduction of the power consumption to a value of 90 mW for an array of four MOSFETs at an operating temperature of 170 °C. Three of the MOSFETs have their gate covered with thin catalytic metals and are used as gas sensors. The fourth one has a standard gate covered with nitride and could act as a reference. The sensor was tested under different gaseous atmospheres and has shown good gas sensitivities to hydrogen and ammonia. The low-power MOSFET array gas sensor presented is suitable for applications in portable gas sensor instruments, electronic noses, and automobiles.
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| 6. |
- Briand, D., et al.
(författare)
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Modulated operating temperature for MOSFET gas sensors : Hydrogen recovery time reduction and gas discrimination
- 2003
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Ingår i: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 93:1-3, s. 276-285
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This communication presents a modulated mode of operation for MOSFET gas sensors. A low-power micromachined device allows pulsing the temperature of MOSFET gas sensors with a time constant less than 100ms. Modulating the temperature during the gas exposure modifies the kinetics of the gas reactions with the sensing film. The way the sensor response is modified by the temperature modulation depends on the sensor "history", on the nature of the surrounding gaseous atmosphere, and on the type of materials used as catalytic sensing film. Pulsing the temperature up just after the gas exposure can reduce the recovery time for specific applications, such as for hydrogen detection. Cycling the temperature can allow the discrimination between different gas mixtures. Discrimination was shown for gaseous mixtures of hydrogen and ammonia in air. The results obtained indicate that a "smart" combination of sample and temperature profile could be used to expand the information content in the sensor response. © 2003 Elsevier Science B.V. All rights reserved.
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| 7. |
- Briand, D., et al.
(författare)
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Thermally isolated MOSFET for gas sending application
- 2001
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Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 22:1, s. 11-13
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Tidskriftsartikel (refereegranskat)abstract
- This work reports on thermally isolated electronic components for gas sensing applications. The device is composed of an array of 4 MOSFET, a diode and a semiconductor resistor integrated on a micro-hotplate, which is fabricated using bulk micromachining of silicon. The thermal efficiency of the device is 2°C/mW with a thermal constant less than 100 ms. Holes are made in the passivation film over the gates of the MOSFET and gas sensitive films deposited on top of the gate insulator. The low thermal mass device realized allows new modes of operation for MOSFET gas sensors such as a combination of the field and thermal effects and a pulsed temperature mode of operation.
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| 8. |
- Eriksson, Mats, 1963-, et al.
(författare)
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Drinking water monitoring with voltammetric sensors
- 2011
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Ingår i: Procedia Engineering. - : Elsevier. - 1877-7058. ; 25, s. 1165-1168
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Tidskriftsartikel (refereegranskat)abstract
- Pulsed voltammetry has been applied to drinking water monitoring. This non-selective technique facilitates detection of several different threats to the drinking water. A multivariate algorithm shows that anomaly detection is possible with a minimum of false alarms. Multivariate analysis can also be used to classify different types of substances added to the drinking water. Low concentrations of sewage water contaminating the drinking water can be detected. A network of such sensors is envisaged to facilitate real-time and on-line monitoring of drinking water distribution networks.
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| 9. |
- Eriksson, Mats, et al.
(författare)
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Event Detection in Crisis Management Systems
- 2009
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Ingår i: Procedia Chemistry. - : Elsevier. - 1876-6196. ; 1:1, s. 1055-1058
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Tidskriftsartikel (refereegranskat)abstract
- The EVENT project concerns drinking water surveillance and includes sensors and algorithms that detect anomalies in the drinking water properties, communication of the evaluated sensor data to a crises management system and presentation of information that is relevant for the end users of the crises management system. We have chosen to focus on a sensor technique based on an "electronic tongue", since this robust type of non-selective sensor, can detect a plurality of anomalies without the need of a specific sensor for each type of event. Measurements of natural variations and contamination events are presented and discussed.
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| 10. |
- Harfeldt, Kristin, et al.
(författare)
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Spectroscopic differences in posterior insula in patients with chronic temporomandibular pain
- 2018
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Ingår i: Scandinavian Journal of Pain. - : De Gruyter Open. - 1877-8860 .- 1877-8879. ; 18:3, s. 351-361
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Chronic pain including temporomandibular disorder (TMD) pain involves a complex interplay between peripheral and central sensitization, endogenous modulatory pathways, cortical processing and integration and numerous psychological, behavioral and social factors. The aim of this study was to compare spectroscopic patterns of N-Acetyl-aspartate (NAA), total creatine (tCr), choline (Cho), myo-inositol (MI), glutamate (Glu), and the combination of Glu and glutamine in the posterior insula in patients with chronic generalized or regional chronic TMD pain (gTMD and rTMD, respectively) compared to healthy individuals (HI) in relation to clinical findings of TMD pain. Methods: Thirty-six female patients with chronic rTMD or gTMD with at least 3 months duration were included in the study. Ten healthy women were included as controls. All participants completed a questionnaire that comprised assessment of degrees of depression, anxiety, stress, catastrophizing, pain intensity, disability and locations. A clinical Diagnostic Criteria for Temporomandibular Disorders examination that comprised assessment of pain locations, headache, mouth opening capacity, pain on mandibular movement, pain on palpation and temporomandibular joint noises was performed. Pressure-pain threshold (PPT) over the masseter muscle and temporal summation to pressure stimuli were assessed with an algometer. Within a week all participants underwent non-contrast enhanced MRI on a 3T MR scanner assessing T1-w and T2-w fluid attenuation inversion recovery. A single-voxel H-1-MRS examination using point-resolved spectroscopy was performed. The metabolite concentrations of NAA, tCr, Cho, MI, Glu and Glx were analyzed with the LC model. Metabolite levels were calculated as absolute concentrations, normalized to the water signal. Metabolite concentrations were used for statistical analysis from the LC model if the Cramer-Rao bounds were less than 20%. In addition, the ratios NAA/tCr, Cho/tCr, Glu/tCr and MI/tCr were calculated. Results: The results showed significantly higher tCr levels within the posterior insula in patients with rTMD or gTMD pain than in HI (p = 0.029). Cho was negatively correlated to maximum mouth opening capacity with or without pain (r(s) = -0.42, n = 28, p = 0.031 and r(s) = -0.48, n = 28, p = 0.034, respectively) as well as pressure-pain threshold on the hand (r(s) = -0.41, n = 28, p = 0.031). Glu was positively correlated to temporal summation to painful mechanical stimuli (r(s) = 0.42, n = 26, p = 0.034). Conclusions: The present study found that increased concentrations of Cho and Glu in the posterior insular cortex is related to clinical characteristics of chronic TMD pain, including generalized pain. These findings provide new evidence about the critical involvement of the posterior insular cortex and the neurobiology underlying TMD pain in both regional and generalized manifestations. Implications: The findings in this study have indirect implications for the diagnosis and management of TMD patients. That said, the findings provide new evidence about the critical involvement of the posterior insular cortex and the neurobiology underlying TMD pain in both regional and generalized manifestations. It is also a further step towards understanding and accepting chronic pain as a disorder in itself.
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| 11. |
- Hellgren, Niklas, et al.
(författare)
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Electronic structure of carbon nitride thin films studied by X-ray spectroscopy techniques
- 2005
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 471:02-jan, s. 19-34
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Tidskriftsartikel (refereegranskat)abstract
- Magnetron-sputtered carbon nitride thin films with different structures and compositions were analyzed by X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS), as well as X-ray emission spectroscopy (XES). In all techniques, the carbon spectra are broad and featureless with little variation depending on growth conditions. The nitrogen spectra, on the other hand, show more distinct features, providing a powerful tool for structural characterization. By comparing the experimental spectra with calculations on different model systems, we are able to identify three major bonding structures of the nitrogen-N1: nitrile (C equivalent to N) bonds; N2: Pyridine-like N, i.e., N bonded to two C atoms; and N3: graphite-like N, i.e., N bonded to three C atoms as if substituted in a graphitic network, however, possibly positioned in a pentagon and/or with sp(3) carbon neighbors. The presence of N2 and N3 are best detected by XPS, while N1 is better detected by NEXAFS. The calculated XES spectra also give good indications how valence band spectra should be interpreted. Films grown at the higher temperatures ( greater than or equal to 350 degreesC) show a pronounced angular dependence of the incoming photon beam in NEXATS measurements, which suggests a textured microstructure with standing graphitic basal planes, while amorphous films grown at low temperatures show isotropic properties.
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| 12. |
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| 13. |
- Hellgren, N., et al.
(författare)
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Nitrogen bonding structure in carbon nitride thin films studied by soft x-ray spectroscopy
- 2001
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 79:26, s. 4348-4350
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Tidskriftsartikel (refereegranskat)abstract
- Soft x-ray absorption (SXAS) and emission (SXES) spectroscopies were applied to study the nitrogen bonding structure in magnetron sputtered CNx thin films. By comparing with calculated spectra of N in different model systems, N in three main bonding environments can be identified: (i) C equivalent toN bonds, with a sharp SXAS peak at 399.5 eV, (ii) pyridine-like N (i.e., N bonded to two C atoms), with an x-ray absorption resonance at similar to 398.5 eV, and (iii) N substituted in graphite, possibly with one sp(3) carbon as a neighbor (SXAS energy similar to 401 eV). These bondings are present in all CNx films analyzed; however, as shown earlier, the relative intensities between the peaks may vary with the growth conditions. Differences in the coordination of the nearest or second nearest C neighbors only cause slight changes in the peak positions and spectrum shape.
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| 14. |
- Lundström, Ingemar, et al.
(författare)
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Artificial 'olfactory' images from a chemical sensor using a light-pulse technique
- 1991
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 352:6330, s. 47-50
-
Tidskriftsartikel (refereegranskat)abstract
- THERE is much interest in the use of chemical sensor arrays, in conjunction with pattern-recognition routines, for developing artificial olfactory devices-electronic noses-which can characterize the chemical composition of gas mixtures 1-5. Here we describe a technique that uses a continuous sensing surface and a detection method involving a scanning pulsed light source, to generate images that represent a fingerprint of the gases detected. The detector is a large-area field-effect device with a number of different catalytic metals constituting the detecting surface (the devices active gate) 6,7. A pulsed light beam scanned across this surface generates a photocapacitive current that varies with the value of the surface potential 8,9. A continuous sensing surface of this type provides information that would require an array of hundreds of discrete sensors. The technique also provides a new means of studying the coupling between the electronic properties of catalytic metals and chemical reactions taking place on their surfaces.
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| 15. |
- Lundström, Ingemar, et al.
(författare)
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Catalytic metals and field-effect devices—a useful combination
- 1990
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 1:1-6, s. 15-20
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Tidskriftsartikel (refereegranskat)abstract
- The properties of gas-sensitive field-effect devices with catalytic metal gates are described. We demonstrate especially how the selectivity of these sensors depends on parameters such as the choice of catalytic metal, the structure of the catalytic metal film and the operation temperature of the device. The sensitivity towards molecules like hydrogen, ammonia, ethanol and ethylene is demonstrated. The selectivity pattern of devices with catalytic metal gates is discussed in relation to the fabrication of multisensor arrays and the development of 'artificial olfactory senses'.
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| 16. |
- Lundström, Ingemar, et al.
(författare)
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From hydrogen sensors to olfactory images — twenty years with catalytic field-effect devices
- 1993
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 13:1-3, s. 16-23
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Tidskriftsartikel (refereegranskat)abstract
- A personal description of the history of gas-sensitive field-effect devices is given. It is shown how the originally described palladium-gate metal-oxide-semiconductor field-effect transistor has developed into sensing surfaces enabling the production of response images to odours. Images obtained for the odour from different cheeses are presented as examples of such artificial olfactory images.
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| 17. |
- Lundström, Ingemar, et al.
(författare)
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Microanalysis Systems for Gases
- 1995
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Ingår i: Micro Total Analysis Systems, 1994. - : Kluwer Academic Publishers. - 0792332172 ; , s. 153-163
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Lundström, Ingemar, 1941-, et al.
(författare)
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Twenty-five years of field effect gas sensor research in Linköping
- 2007
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 121:1, s. 247-262
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Tidskriftsartikel (refereegranskat)abstract
- The present contribution contains an overview of the development of gas sensitive field-effect devices in Linköping during the last 25 years. It is completely centred to the work at the Laboratory of Applied Physics at Linköping University, and is therefore not a proper review of a research field where many important contributions have been made by several other research groups. © 2006 Elsevier B.V. All rights reserved.
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| 19. |
- Sjögren, Erik, 1977-, et al.
(författare)
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The effect of intradermal microdosing of a transient receptor potential cation channel subfamily V member 1 antagonist on heat evoked pain and thermal thresholds in normal and ultraviolet-C exposed skin in healthy volunteers
- 2019
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Ingår i: European Journal of Pain. - : WILEY. - 1090-3801 .- 1532-2149. ; 23:10, s. 1767-1779
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Tidskriftsartikel (refereegranskat)abstract
- Background Three TRPV1 (Transient Receptor Potential Vanilloid Receptor 1) antagonists were developed for testing in situ in human skin (Sjogren et al., 2016; Sjogren et al., 2018; Sjogren et al., 2018). The first human study using these compounds and capsaicin, was performed to determine the required local antagonist concentrations needed for target engagement (Proof of Mechanism, PoM) (Sjogren et al., 2018). In this paper, the aim was to address a TRPV1 antagonist's ability to inhibit a more complex pain signal and to define translational endpoints that could be used in further drug development, when progressing orally bioavailable TRPV1 antagonists as novel analgesic medications. Method This was a single centre, placebo-controlled, clinical proof of principle (PoP) study in 25 healthy volunteers. The subjects were exposed to UV irradiation, causing a local tissue inflammation. Three different doses of AZ12048189 were administered to assess pain perception through quantitative sensory testing (QST) and erythema using Laser Doppler scanning. Results AZ12048189 increased the warmth detection threshold (WDT) and the heat pain threshold (HPT) and decreased the intensity of supra threshold heat pain (STHP). AZ12048189 did not, however, have any significant effects as assessed using mechanical stimulation or Laser Doppler. Conclusions This study validated translational tools to confirm target engagement for TRPV1 antagonists; WDT, HPT and STHP have utility in this respect, after oral administration of a TRPV1 antagonist. This study also proved that TRPV1 antagonists can inhibit a more complex, non-capsaicin dependent thermally induced pain signal.
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| 20. |
- Ulrich, Christian, 1976-, et al.
(författare)
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Simultaneous estimation of soot and diesel contamination in engine oil using electrochemical impedance spectroscopy
- 2007
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 127:2, s. 613-618
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we explore the combination of electrochemical impedance spectroscopy and multivariate data analysis to simultaneously predict the concentrations of soot and diesel in engine oil. For this purpose, we use a well defined measurement set-up to minimize interference from ambient noise, and to obtain a large amount of data in a short period of time. An imperative requirement is that soot and diesel affect the impedance in different ways over the employed frequency range. It was, for example, found that diesel had a larger influence at lower frequencies. Using partial least squares modelling we show that it is possible to simultaneously predict the concentrations of both soot and diesel in engine oil. Since the temperature in an engine varies, the influence of the oil temperature is investigated in a preliminary experiment. This study is a part of the development of an electrochemical on-board sensor for real-time monitoring of engine oil.
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| 21. |
- Winquist, Fredrik, et al.
(författare)
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Visual images of gas mixtures produced with field-effect structures
- 1992
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 6:1-3, s. 157-161
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Tidskriftsartikel (refereegranskat)abstract
- The details of a recently demonstrated possibility of making two-dimensional response maps of a gas mixture are discussed. It is described how maps of work-function changes due to the interaction between molecules like ethanol and ammonia and thin catalytic metal films as gates on field-effect structures can be created with a scanning light-pulse technique. Simple image processing is shown to enhance the differences in the response patterns created by different molecules.
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| 22. |
- Zubkans, J., et al.
(författare)
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In-situ modification of the NOx sensitivity of thin discontinuous platinum films as gates of chemical sensors
- 1995
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 268:1-2, s. 140-143
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Tidskriftsartikel (refereegranskat)abstract
- It is shown how chemically sensitive metal-oxide semiconductor field-effect transistors with a thin discontinuous platinum gate can be modified for the detection of NOx. After a pulse of ammonia the sensors show an increased sensitivity to NOx. The threshold voltage shift induced by NOx is opposite to the direction before the ammonia pulse. The threshold voltage now increases due to NOx exposure, while hydrogen, ammonia and hydrocarbons cause a decrease of the threshold voltage. The temperature dependence of the NOx sensitivity suggests that after the ammonia pulse there are two competing polarisation phenomena caused by the interaction between NOx and the sensing surface. The results are of general interest since they indicate how thin sensing layers can be modified after fabrication to promote sensitivity towards specific molecules. Furthermore they shed some new light on the detection mechanisms of thin discontinuous metal gates.
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