| 1. |
- Edwards, M.J., et al.
(författare)
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Pressure and temperature dependence of GaN/AlGaN high electron mobility transistor based sensors on a sapphire membrane
- 2012
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Ingår i: Physica Status Solidi (C) Current Topics in Solid State Physics. - : Wiley. - 1862-6351. ; 9, s. 960-963
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports a high pressure sensor based on a GaN/AlGaN High Electron Mobility Transistor (HEMT) that uses its 375 mm thick sapphire substrate to provide a robust base and enables device operation up to at least 60 bar (6 MPa). Transduction of changes in ambient pressure occurs via piezoelectric and pyroelectric effects on the channel conductance. The HEMTs were strategically placed along an 8 mm 2 GaN/AlGaN/GaN/sapphire chip; where the central 4 mm diameter behaves as a pressure sensitive 'drumskin'. The location of peak response lies in the HEMT at the geometric centre of the drumskin, demonstrated by the change in I DS when the pressure was increased from 0 to 60 bar. The response of six strategically placed HEMTs along the chip's surface, were compared to a finite element model to predict sensor behaviour. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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| 2. |
- Edwards, Michael, et al.
(författare)
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Modelling and optimisation of a sapphire/GaN-based diaphragm structure for pressure sensing in harsh environments
- 2010
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Ingår i: Conference Proceedings - The 8th International Conference on Advanced Semiconductor Devices and Microsystems, ASDAM 2010. - 9781424485758 ; , s. 127-130
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Konferensbidrag (refereegranskat)abstract
- GaN is a potential sensor material for harsh environments due to its piezoelectric and mechanical properties. In this paper an 8mm diameter sensor structure is proposed based on a GaN / AlGaN / sapphire HEMT wafer. The discs will be glass-bonded to an alumina package, creating a 'drumskin' type sensor that is sensitive to pressure changes. The electromechanical behaviour of the sensor is studied in an attempt to optimise the design of a pressure sensor (HEMT position and sapphire thickness) for operation in the range of 10 - 50 bar (5 MPa) and above 300°C. ©2010 IEEE.
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| 3. |
- Xiao, H., et al.
(författare)
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Hydraulic Pressure Ripple Energy Harvesting : Structures, Materials, and Applications
- 2022
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6832 .- 1614-6840. ; 12:9
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Forskningsöversikt (refereegranskat)abstract
- The need for wireless condition monitoring and control of hydraulic systems in an autonomous and battery-free manner is attracting increasing attention in an effort to provide improved sensing functionality, monitoring of system health, and to avoid catastrophic failures. The potential to harvest energy from hydraulic pressure ripples and noise is particularly attractive since they inherently have a high energy intensity, which is associated with the hydraulic mean pressure and flow rate. This paper presents a comprehensive overview of the state of the art in hydraulic pressure energy harvesting, which includes the fundamentals of pressure ripples in hydraulic systems, the choice of electroactive materials and device structures, and the influence of the fluid–mechanical interface. In addition, novel approaches for improving the harvested energy and potential applications for the technology are discussed, and future research directions are proposed and outlined.
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