| 1. |
- Berglund, Martin, 1985-, et al.
(författare)
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Extreme-temperature lab on a chip for optogalvanic spectroscopy of ultra small samples – key components and a first integration attempt
- 2016
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Ingår i: 27th Micromechanics And Microsystems Europe Workshop (MME 2016). - : Institute of Physics (IOP).
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Konferensbidrag (refereegranskat)abstract
- This is a short summary of the authors’ recent R&D on valves, combustors, plasma sources, and pressure and temperature sensors, realized in high-temperature co-fired ceramics, and an account for the first attempt to monolithically integrate them to form a lab on a chip for sample administration, preparation and analysis, as a stage in optogalvanic spectroscopy.
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| 2. |
- Khaji, Zahra, et al.
(författare)
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Design and fabrication of a miniaturized combustor with integrated oxygen storage and release element
- 2014
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Ingår i: 25th Micromechanics and Microsystems Europe workshop (MME 2014),2014, P19 (4 pp).
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Konferensbidrag (refereegranskat)abstract
- A miniature combustor for converting organic samples into CO2 with application in carbon isotopic measurements of small samples has been manufactured and evaluated. The combustor was made by machining and laminating High-Temperature Co-fired Ceramic (HTCC) 99.99% alumina green tapes and screen printing platinum conductors on them. The device has a built-in heater and a temperature sensor made of platinum, which were co-sintered with the ceramic. A metal oxide (copper oxide) oxygen supply was added to the combustor after sintering by in-situ electroplating of copper on the heater pattern followed by thermal oxidation. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Thermal Gravimetric Analysis (TGA) were used to study electroplating, oxidation and the oxide decompo-sition processes.
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| 3. |
- Khaji, Zahra, et al.
(författare)
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Investigation of the storage and release of oxygen in a Cu-Pt element of a high-temperature microcombustor
- 2014
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Ingår i: The 14th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications(PowerMEMS 2014). - : Institute of Physics (IOP).
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Konferensbidrag (refereegranskat)abstract
- A miniature combustor for converting organic samples into CO2 with application in carbon isotopic measurements has been manufactured and evaluated. The combustor was made of High-Temperature Co-fired Ceramic (HTCC) alumina green tapes. The device has a built-in screen printed heater and a temperature sensor made of platinum, co-sintered with the ceramic. A copper oxide oxygen supply was added to the combustor after sintering by in-situ electroplating of copper on the heater pattern followed by thermal oxidation. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Thermal Gravimetric Analysis (TGA) were used to study electroplating, oxidation and the oxide reduction processes. The temperature sensor was calibrated by use of a thermocouple. It demonstrates a temperature coefficient resistance of 4.66×10−3/°C between 32 and 660 °C. The heat characterization was done up to 1000 °C by using IR thermography, and the results were compared with the data from the temperature sensor. Combustion of starch confirmed the feasibility of using copper oxide as the source of oxygen of combustion.
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| 4. |
- Khaji, Zahra, et al.
(författare)
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Manufacturing and characterization of a ceramic microcombustor with integrated oxygen storage and release element
- 2015
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Ingår i: Journal of Micromechanics and Microengineering. - Bristol : Institute of Physics (IOP). - 0960-1317 .- 1361-6439. ; 25:10
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Tidskriftsartikel (refereegranskat)abstract
- A microscale ceramic high-temperature combustor with a built-in temperature sensor and source of oxygen has been designed, manufactured and characterized. The successful in situ electroplating and oxidation of copper, and the use of copper oxide as the source of oxygen were demonstrated. It was shown that residual stresses from electroplating, copper oxidation and oxide decomposition did not cause much deformation of the substrate but influenced mainly the integrity and adhesion of the metal films. The process had influence on the electrical resistances, however. Calibration of the temperature sensor and correlation with IR thermography up to 1000°C revealed a nearly linear sensor behavior. Demonstration of combustion in a vacuum chamber proved that no combustion had occurred before release of oxygen from the metal oxide resource.
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| 5. |
- Knaust, Stefan, et al.
(författare)
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Characterization of dielectric properties of polycrystalline aluminum nitride for high temperature wireless sensor nodes
- 2013
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Ingår i: Journal of Physics. - London : Institute of Physics (IOP).
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Konferensbidrag (refereegranskat)abstract
- An aluminium nitride (AlN) passive resonance circuit intended for thermallymatched high temperature wireless sensor nodes (WSN) was manufactured using thick-lmtechnology. Characterization was done for temperatures up to 900C in both a hot-chuck forfrequencies below 5 MHz, and using wireless readings of resonating circuits at 15 MHz, 59 MHz,and 116 MHz. The substrate for the circuits was sintered polycrystalline AlN. Using a simpliedmodel for the resonators where the main contribution of the frequency-shift was considered tocome from a shift of the dielectric constant for these frequencies, the temperature dependency ofthe dielectric constant for AlN was found to decrease with increasing frequency up to 15 MHz.With an observed frequency shift of 0.04% at 15 MHz, and up to 0.56% at 59 MHz over atemperature range of 900C, AlN looks as a promising material for integration of resonancecircuits directly on the substrate.
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| 6. |
- Persson, Anders, et al.
(författare)
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Optogalvanic spectroscopy with microplasma sources – Current status and development towards Lab-On-A-Chip
- 2015
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Konferensbidrag (refereegranskat)abstract
- Miniaturized optogalvanic spectros-copy shows excellent prospects of becoming a highly sensitive method for gas analysis in micro total analysis systems. Here, a status report on the current development of microplasma sources for optogalvan-ic spectroscopy is presented, together with the first comparison of the sensitivity of the method to con-ventional single-pass absorption spectroscopy. The stability and reproducibility of the microplasma source when used as a detector for optogalvanic spectroscopy is also investigated, and a roadmap of future developments is presented, with the particular focus of integrating sensors for measuring the pres-sure, temperature and flow of the sample gas through the detector, and combining the detector with a miniaturized combustor to allow for studies of solid samples.
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| 7. |
- Persson, Anders, et al.
(författare)
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Optogalvanic spectroscopy with microplasma sources – Current status and development towards lab on a chip
- 2016
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 26:10
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Tidskriftsartikel (refereegranskat)abstract
- Miniaturized optogalvanic spectroscopy (OGS) shows excellent prospects of becoming ahighly sensitive method for gas analysis in micro total analysis systems. Here, a status reporton the current development of microwave induced microplasma sources for OGS is presented,together with the first comparison of the sensitivity of the method to conventional single-passabsorption spectroscopy. The studied microplasma sources are stripline split-ring resonators(SSRRs), with typical ring radii between 3.5 and 6 mm and operation frequencies around2.6 GHz. A linear response (R2 = 0.9999), and a stability of more than 100 s are demonstratedwhen using the microplasma source as an optogalvanic detector. Additionally, saturationeffects at laser powers higher than 100 mW are observed, and the temporal response of theplasma to periodic laser perturbation with repletion rates between 20 Hz and 200 Hz arestudied. Finally, the potential of integrating additional functionality with the detector isdiscussed, with the particular focus on a pressure sensor and a miniaturized combustor toallow for studies of solid samples.
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| 8. |
- Sturesson, Peter, 1981-, et al.
(författare)
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Ceramic Pressure Sensor for High Temperatures – Investigation of the Effect of Metallizationon on Read Range
- 2017
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 17:8, s. 2411-2421
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Tidskriftsartikel (refereegranskat)abstract
- A study on the relationship between circuit metallization, made by double-layer screen printing of platinum and electroplating of silver on top of platinum, and its impact on practical read range of ceramic LC resonators for high-temperature pressure measurements is presented. Also included is the first realization of membranes by draping a graphite insert with ceramic green body sheets. As a quality factor circuit reference, two-port microstrip meander devices were positively evaluated and to study interdiffusion between silver and platinum, test samples were annealed at 500 degrees C, 700 degrees C, and 900 degrees C for 4, 36, 72, and 96 h. The LC resonators were fabricated with both metallization methods, and the practical read range at room temperature was evaluated. Pressure-sensitive membranes were characterized for pressures up to 2.5 bar at room temperature, 500 degrees C and up to 900 degrees C. Samples electroplated with silver exhibited performance equal to or better than double-layer platinum samples for up to 60 h at 500 degrees C, 20 h at 700 degrees C, and for 1 h at 900 degrees C, which was correlated with the degree of interdiffusion as determined from cross-sectional analysis. The LC resonator samples with double-layer platinum exhibited a read range of 61 mm, and the samples with platinum and silver exhibited a read range of 59 mm. The lowest sheet resistance, and, thereby, the highest read range of 86 mm, was obtained with a silver electroplated LC resonator sample after 36 h of annealing at 500 degrees C.
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| 9. |
- Sturesson, Peter, et al.
(författare)
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Thermomechanical behaviour and pressure sensing of ceramic wireless devices for high-temperature environments
- 2014
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Konferensbidrag (refereegranskat)abstract
- This paper reports on the design, fabrication and thermomechanical characterization of wirelessceramic devices, one with an integrated pressure sensor element. The project aims at developingmicrosystems for sensing in harsh environments where conventional electronic devices are restrained.Here, the devices are LC resonating circuits made from High-Temperature Co-fired Ceramic (HTCC)aluminium oxide green tapes. For the fabrication, the tapes were screen-printed with platinum paste,micromachined, stacked, laminated and fired. The additional sensor element was made from the samematerial and with the same processes, and contains a cavity sealed with a capacitive membrane.Thermomechanical characterization was made by investigating the bimorphic behaviour due to CTEmismatch as well as the resonance frequency of the devices as a function of mechanical displacement.Also, the resonance frequency as a function of pressure was demonstrated for the device with anintegrated pressure sensor node. The wireless readings were performed with a tuneable resonating loopantenna. The devices showed a relatively low quality factor value. The bimorphic behaviour is lowwith only small variations for temperatures up to 400°C. As for the mechanical displacement, theresonance frequency was only affected for thin devices at forced deformations that were larger thanthose observed as a function of temperature. For the device with an integrated pressure sensor, a clearpressure-induced frequency shift of 6785 ppm was observed at 1.5 bar. This indicates that the devicesare robust for high temperatures and also applicable for pressure readings. Future work will furtherexpand on high-temperature characterization of the devices.
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| 10. |
- Sturesson, Peter, et al.
(författare)
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Thermomechanical properties and performance of ceramic resonators for wireless pressure reading at high temperatures
- 2015
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Ingår i: Journal of Micromechanics and Microengineering. - Bristol : Institute of Physics Publishing (IOPP). - 0960-1317 .- 1361-6439. ; 25:9
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the design, fabrication, and thermomechanical study of ceramic LC resonators for wireless pressure reading, verified at room temperature, at 500 °C and at 1000 °C for pressures up to 2.5 bar. Five different devices were fabricated from high-temperature co-fired ceramics (HTCC) and characterized. Alumina green tape sheets were screen printed with platinum paste, micromachined, laminated, and fired. The resulting samples were 21 mm × 19 mm with different thicknesses. An embedded communicator part was integrated with either a passive backing part or with a pressure-sensing element, including an 80 µm thick and 6 mm diameter diaphragm. The study includes measuring thermally and mechanically induced resonance frequency shifts, and thermally induced deformations. For the pressure sensor device, contributions from changes in the relative permittivity and from expanding air trapped in the cavity were extracted. The devices exhibited thermomechanical robustness during heating, regardless of the thickness of the backing. The pressure sensitivity decreased with increasing temperature from 15050 ppm bar−1 at room temperature to 2400 ppm bar−1 at 1000 °C, due to the decreasing pressure difference between the external pressure and the air pressure inside the cavity.
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