Browsing by Author "Tsai, Jeff Tsung-Hui"

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MESOPOROUS CARBON POWDER GAS SENSORS FOR DETECTION OF CARBON MONOXIDE
(2009-12-01)
Lu, Chih-Cheng
;
Liao, Kuan-Hsun
;
Tsai, Jeff Tsung-Hui
;
Liu, Chueh-Yang
;
Leu, Jih-Perng
This article reports a new class of silicon-based microgas sensors utilizing hexagonally-ordered mesoporous carbon powders (MCPs) as the sensitive film. The mesoporous carbon powders featuring high-specific surface area are replicated by the SBA-15 silica template and immobilized between Cr electrodes on a 9 x 9 cm silicon chip by using a. c. dielectrophoresis (DEP) process at room temperature. The silicon sensor platform comprises Cr microheaters embedded in a dielectric thin membrane manufactured by microelectromechanical systems back-etching techniques. It is shown that MCPs can be satisfactorily aligned along electric fields and accumulated to the electrode area. Investigations into CO detection are carried out to verify gas-sensitive characteristics of the MCP nanofilm. Our experimental results disclose the mesoporous carbon powders are successfully chemoresistive to CO, and demonstrate distinct resistance change with respect to ppm-level variation. In addition, response time, recovery time, and reproducible sensing behavior are experimentally obtained.