Date of Award

3-1993

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Electrical and Computer Engineering

First Advisor

Edward S. Kolesar, PhD

Abstract

This investigation designed and developed a miniature gas chromatograph (GC) using silicon micromachining techniques. The GC is composed of a miniature sample injector (10 µl sample loop); a 0.9 m long, rectangular-shaped (300 µm width and 10 micrometers height) capillary column coated with a 0.2 µm thick copper phthalocyanine (CuPc) stationary phase; and a dual-detector scheme incorporating a CuPc-coated chemiresistor and a 125 µm diameter thermal conductivity detector bead. Micromachining was employed to fabricate the sample injector interface, the GC column, and the dual-detector cavity. A novel processing technique was developed to sublime the CuPc stationary phase coating on the GC column walls. The miniature GC system has been used to separate parts-per-million ammonia and nitrogen dioxide concentrations in less than 30 minutes (10 µl sample injected at 40 psi). A secondary discovery was the heat of adsorption of nitrogen dioxide (0.38 eV) on a polycrystalline CuPc film (0.2 µm thick) . This research demonstrated the utilization of a miniature GC to investigate the adsorptive properties of thin films. Also, the time-domain performance model of the miniature GC developed in this investigation will facilitate the optimization of future miniature GC designs.

AFIT Designator

AFIT-DS-ENG-93M-01

DTIC Accession Number

ADA262594

Comments

The author's Vita page is omitted.

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