From 2010-2012, as graduate student in mechanical engineering at the University of Massachusetts Lowell, I researched resistive sensors. These Graphene sensors were being tested for thier ability to detect chemical traces of explosives. I fabricated and tested sensors coated with Graphene using photo-lithography and groove-and-fill techniques. Additionally, a battery powered micro-controller based device was created, employing a four point probe, to demonstrate the system's portability.
I wrote and defended my thesis obtaining my master's degree in 2012. My thesis title and abstract follows.
Flexible Explosive Sensors using Hydrazine Graphene on Molded Channel Circuit Electrodes
Explosive detection is of great importance to the government, military and civilians. The simplicity of resistive type sensors holds great promise for making low cost and portable sensors. This thesis explores a specific class of flexible chemoresistive sensors combining a Polyethylene Terephthalate (PET) substrate, channel circuit electrodes using silver paste, and a resistive layer created from Hydrazine Graphene (HG). The HG reacts with air forming graphene oxide. Results of tests show that successful circuits can be fabricated based upon "groove & fill" techniques using Polydimethylsiloxane (PDMS) molds with trace widths at least down to \(100\mu m\) wide. Dinitrotoulene 2,4 (DNT) was detected using layers of HG drop coated on electrodes. Additionally, four explosive sensor test environments are evaluated. A proof of concept for portable sensor electronics is developed. Finally, recommendations for improvements and future work are presented.