Date of Award


Degree Type


Degree Name

Master of Science in Chemical Engineering (MSChE)


Chemical Engineering

First Advisor

Otto J. Gregory


There is a growing need for a continuous monitoring system that can detect explosives in the vapor phase at trace levels. For example, triacetone triperoxide (TATP), an explosive commonly used by terrorists in improvised explosive devices (IEDs) is still going largely undetected in many densely populated venues. No electronic trace detection system currently exists that is capable of continuously monitoring TATP vapors or its precursors. Solid-state metal-oxide sensors have demonstrated the ability to successfully detect TATP. However, to improve sensor sensitivity, the large thermal mass associated with these solid-state sensors was dramatically reduced by replacing them with extremely low mass (25 μm diameter) coil microheaters. These coil microheaters have a thermal mass that is two orders of magnitude less than the solid-state sensors and resulted in much greater signal-to-noise ratios with excellent selectivity amongst metal-oxides. These sensors were able to detect TATP, 2,4-DNT and ammonium nitrate vapors at the 20 ppm level under varied conditions including sensor temperature, catalyst material used, inlet flow rate (sampling rate) and humidity.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.