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Title: NOVEL MEMS CHENICAL SENSORS FOR GASIFICATION

Authors:
Publication Date:
Research Org.:
TRANSDUCER TECHNOLOGFY, INC, NEWARK, CA
Sponsoring Org.:
USDOE
OSTI Identifier:
897831
Report Number(s):
DOE/ER/84109/F
DOE Contract Number:
FG02-04ER84109
Type / Phase:
SBIR
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
10 SYNTHETIC FUELS; 04 OIL SHALES AND TAR SANDS; SENSORS, GASIFICATION, OIL SHALE, SYNTHETIC FUELS, CONVERSION

Citation Formats

JOSEPH R STETTER, PHD. NOVEL MEMS CHENICAL SENSORS FOR GASIFICATION. United States: N. p., 2007. Web.
JOSEPH R STETTER, PHD. NOVEL MEMS CHENICAL SENSORS FOR GASIFICATION. United States.
JOSEPH R STETTER, PHD. Tue . "NOVEL MEMS CHENICAL SENSORS FOR GASIFICATION". United States. doi:.
@article{osti_897831,
title = {NOVEL MEMS CHENICAL SENSORS FOR GASIFICATION},
author = {JOSEPH R STETTER, PHD},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 23 00:00:00 EST 2007},
month = {Tue Jan 23 00:00:00 EST 2007}
}

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  • This report describes a new microsystems technology for the creation of microsensors and microelectromechanical systems (MEMS) using stress-free amorphous diamond (aD) films. Stress-free aD is a new material that has mechanical properties close to that of crystalline diamond, and the material is particularly promising for the development of high sensitivity microsensors and rugged and reliable MEMS. Some of the unique properties of aD include the ability to easily tailor film stress from compressive to slightly tensile, hardness and stiffness 80-90% that of crystalline diamond, very high wear resistance, a hydrophobic surface, extreme chemical inertness, chemical compatibility with silicon, controllable electricalmore » conductivity from insulating to conducting, and biocompatibility. A variety of MEMS structures were fabricated from this material and evaluated. These structures included electrostatically-actuated comb drives, micro-tensile test structures, singly- and doubly-clamped beams, and friction and wear test structures. It was found that surface micromachined MEMS could be fabricated in this material easily and that the hydrophobic surface of the film enabled the release of structures without the need for special drying procedures or the use of applied hydrophobic coatings. Measurements using these structures revealed that aD has a Young's modulus of {approx}650 GPa, a tensile fracture strength of 8 GPa, and a fracture toughness of 8 MPa{center_dot}m {sup 1/2}. These results suggest that this material may be suitable in applications where stiction or wear is an issue. Flexural plate wave (FPW) microsensors were also fabricated from aD. These devices use membranes of aD as thin as {approx}100 nm. The performance of the aD FPW sensors was evaluated for the detection of volatile organic compounds using ethyl cellulose as the sensor coating. For comparable membrane thicknesses, the aD sensors showed better performance than silicon nitride based sensors. Greater than one order of magnitude increase in chemical sensitivity is expected through the use of ultra-thin aD membranes in the FPW sensor. The discoveries and development of the aD microsystems technology that were made in this project have led to new research projects in the areas of aD bioMEMS and aD radio frequency MEMS.« less
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  • This equipment grant permitted purchase of a complete optical-fiber draw facility and auxilliary equipment for the fiber-characterization laboratory. The draw tower was erected in a specially prepared laboratory. It is a 7.8-m automated tower with a 20-kW carbon induction furnace, and sufficient room for two UV coating stages, or a UV coating stage and a thermal-curing stage. The tower installation took perhaps somewhat more time than initially anticipated, largely due to difficulties in the site preparation. The tower itself was installed on a reinforced-concrete pad, with appropriate vibration isolation. Experience was gained in the use of the tower, and kilometermore » lengths of fiber were drawn that range in diameter from 50 to 250 microns, with a tolerance of the order of a few microns. In anticipation of expanding the coating capabilities of the draw tower, a vacuum system was purchased for use with radio-frequency sputtering on-line on the tower. This will be particularly useful for ceramic-coated fibers in the study of the behavior of fiber-strengthened composite materials.« less
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