Journal
SENSORS AND ACTUATORS B-CHEMICAL
Volume 121, Issue 2, Pages 414-422Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.snb.2006.04.107
Keywords
thermal conductivity detector; mu TCD; miniature sensors; micro-ChemLab; boundary element algorithm
Ask authors/readers for more resources
This work describes the design, computational prototyping, fabrication, and characterization of a microfabricated thermal conductivity detector (mu TCD) to analyze the effluent from a micro-gas chromatograph column (mu GC) and to complement the detection efficacy of a surface acoustic wave detector in the micro-ChemLab (TM) system. To maximize the detection sensitivity, we designed a four-filament Wheatstone bridge circuit where the resistors are suspended by a thin silicon nitride membrane in pyramidal or trapezoidal shaped flow cells. The geometry optimization was carried out by simulation of the heat transfer in the devices, utilizing a boundary element algorithm. Within microfabrication constraints, we determined and fabricated nine sensitivity-optimized geometries of the RTCD. The nine optimal geometries were tested with two different flow patterns. We demonstrated that the perpendicular flow, where the gas directly impinged upon the membrane, yielded a sensitivity that is three times greater than the parallel flow, where the gas passed over the membrane. The functionality of the RTCD was validated with the theoretical prediction and showed a consistent linear response to effluent concentrations, with a detection sensitivity of 1 ppm, utilizing less than 1 W of power. (c) 2006 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available