scholarly journals Note: Micro-channel array crucible for isotope-resolved laser spectroscopy of high-temperature atomic beams

2017 ◽  
Vol 88 (12) ◽  
pp. 126101 ◽  
Author(s):  
Vyacheslav Lebedev ◽  
Joshua H. Bartlett ◽  
Alexander Malyzhenkov ◽  
Alonso Castro
Keyword(s):  
High Temperature ◽  
Laser Spectroscopy ◽  
Micro Channel ◽  
Atomic Beams

Aluminum Nitride Micro-Channels Grown via Metal Organic Vapor Phase Epitaxy for MEMs Applications

2007 ◽  
Vol 1040 ◽  
Author(s):  
L. E. Rodak ◽  
Sridhar Kuchibhatla ◽  
P. Famouri ◽  
Ting Liu ◽  
D. Korakakis
Keyword(s):  
High Temperature ◽  
Aluminum Nitride ◽  
Silicon Dioxide ◽  
Vapor Phase ◽  
High Energy ◽  
Vapor Phase Epitaxy ◽  
Micro Channel ◽  
Organic Vapor ◽  
Micro Channels ◽  
Metal Organic

AbstractAluminum nitride (AlN) is a promising material for a number of applications due to its temperature and chemical stability. Furthermore, AlN maintains its piezoelectric properties at higher temperatures than more commonly used materials, such as Lead Zirconate Titanate (PZT) [1, 2], making AlN attractive for high temperature micro and nano-electromechanical (MEMs and NEMs) applications including, but not limited to, high temperature sensors and actuators, micro- channels for fuel cell applications, and micromechanical resonators.This work presents a novel AlN micro-channel fabrication technique using Metal Organic Vapor Phase Epitaxy (MOVPE). AlN easily nucleates on dielectric surfaces due to the large sticking coefficient and short diffusion length of the aluminum species resulting in a high quality polycrystalline growth on typical mask materials, such as silicon dioxide and silicon nitride [3,4]. The fabrication process introduced involves partially masking a substrate with a silicon dioxide striped pattern and then growing AlN via MOVPE simultaneously on the dielectric mask and exposed substrate. A buffered oxide etch is then used to remove the underlying silicon dioxide and leave a free standing AlN micro-channel. The width of the channel has been varied from 5 ìm to 110 ìm and the height of the air gap from 130 nm to 800 nm indicating the stability of the structure. Furthermore, this versatile process has been performed on (111) silicon, c-plane sapphire, and gallium nitride epilayers on sapphire substrates. Reflection High Energy Electron Diffraction (RHEED), Atomic Force Microscopy (AFM), and Raman measurements have been taken on channels grown on each substrate and indicate that the substrate is influencing the growth of the AlN micro-channels on the SiO2 sacrificial layer.

Integrated FP/RFBG sensor with a micro-channel for dual-parameter measurement under high temperature

2017 ◽  
Vol 56 (15) ◽  
pp. 4250 ◽  
Author(s):  
Yaxin Wang ◽  
Haihong Bao ◽  
Zengling Ran ◽  
Jingwei Huang ◽  
Shuang Zhang
Keyword(s):  
High Temperature ◽  
Parameter Measurement ◽  
Micro Channel

Deposition of Pt-catalyst in a micro-channel of a silicon reactor: Application to gas micro-TAS working at high temperature

2006 ◽  
Vol 118 (1-2) ◽  
pp. 297-304 ◽  
Author(s):  
M. Roumanie ◽  
C. Pijolat ◽  
V. Meille ◽  
C. De Bellefon ◽  
P. Pouteau ◽  
...  
Keyword(s):  
High Temperature ◽  
Pt Catalyst ◽  
Micro Channel ◽  
Reactor Application

Design and Development of a Low-Cost, High Temperature Silicon Carbide Micro-Channel Recuperator

2005 ◽  
Author(s):  
Merrill A. Wilson ◽  
Kurt Recknagle ◽  
Kriston Brooks
Keyword(s):  
Heat Transfer ◽  
Silicon Carbide ◽  
High Temperature ◽  
Heat Exchanger ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Ceramic Materials ◽  
Micro Channel ◽  
Micro Channels ◽  
Micro Turbine

Typically, ceramic micro-channel devices are used for high temperature heat exchangers, catalytic reactors, electronics cooling, and processing of corrosive streams where the thermomechanical benefits of ceramic materials are desired. These benefits include: high temperature mechanical and corrosion properties and tailorable material properties such as thermal expansion, electrical conductivity and thermal conductivity. In addition, by utilizing Laminated Object Manufacturing (LOM) methods, inexpensive ceramic materials can be layered, featured and laminated in the green state and co-sintered to form monolithic structures amenable to mass production. In cooperation with the DOE and Pacific Northwest National Labs, silicon carbide (SiC) based micro-channel recuperator concepts are being developed and tested. The performance benefits of a high temperature, micro-channel heat exchanger are realized from the improved thermal efficiency of the high temperature cycles and the improved effectiveness of micro-channels for heat transfer. In designing these structures, the heat and mass transfer within the micro-channels are being analyzed with heat transfer models, computational fluid dynamics models and validated with experimental results. As an example, a typical micro-turbine cycle was modified and modeled to incorporate this ceramic recuperator and it was found that the overall thermal efficiency of the micro-turbine could be improved from about 27% to over 40%. Process improvements require technical advantages and cost advantages. These LOM methodologies have been based on well-proven industry standard processes where labor, throughput and capital estimates have been tested. Following these cost models and validation at the prototype scale, cost estimates were obtained. For the micro-turbine example, cost estimates indicate that the high-temperature SiC recuperator would cost about $200 per kWe. The development of these heat exchangers is multi-faceted and this paper focuses on the design optimization of a layered micro-channel heat exchanger, its performance testing, and fabrication development through LOM methodologies.

Thermo-Mechanical Design of a High-Temperature Silicon Carbide Micro-Channel Heat Exchanger

2003 ◽  
Author(s):  
Merrill A. Wilson ◽  
Steven M. Quist
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Mechanical Design ◽  
Mechanical Degradation ◽  
Micro Channel ◽  
Power Cycles ◽  
Microchannel Heat Exchanger ◽  
Operating Environments

Efficiency and emissions of advanced gas turbine power cycles can be improved by incorporating high-temperature ceramic heat exchangers (see Figure 1). In cooperation with the DOE, preliminary development and testing of SiC based structures has been completed. This program has focused on four initial areas: thermo-mechanical degradation as a function of the chemical operating environments, design of a layered microchannel heat exchanger, thermo-mechanical testing and analysis of these structures, and fabrication development through rapid prototyping techniques.

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