Over the past several decades, the progress in micro fabrication technology has revolutionized the world in such fields as computing, signal processing, and automotive manufacturing. Making various types of instruments smaller is another example of how the use of this technology has produced significant advancements. One such instrument is the gas chromatography system used in a number of scientific, medical, and industrial settings to separate and analyze dangerous, volatile organic compounds in gases, liquids, and solids.
For the past several years, Masoud Agah, an associate professor in Virginia Tech’s Bradley Department of Electrical and Computer Engineering, has used a National Science Foundation award to develop a credit-card-sized gas chromatography platform that can analyze volatile compounds within seconds.
In conducting his research, Agah identified a problem that allowed him to develop his new technology. He explained that the research community has more actively pursued “the hybrid integrated approach” for the development of micro gas chromatography system and this method is relatively “less vibrant in the monolithic integrated approach.” As Agah explained, the hybrid integration approach allows the major components of the system, to be miniaturized individually on separately fabricated chips. These components are then manually assembled using commercially available off-chip fluidic interconnects.
“The manual assembly of the individual components is really a cumbersome job and increases the overall weight and footprint of the micro gas chromatography system,” explained Agah. “To some extent, the hybrid integrated approach is inconsistent with the purpose of micro gas chromatography research since further improvement in terms of size, cost, and performance can be achieved by the single chip or monolithic integration of micro gas chromatography components.”
Agah and his graduate students Muhammad Akbar of Islamabad, Pakistan and Hamza Shakeel of Rawalpindi, Pakistan recently developed a unique gas chromatography–on-chip module. “The gas chromatography on-a-chip provides highly efficient separations and detection, reduced analysis times using temperature and flow programming, as well as fast detection response times suitable for high-speed gas chromatography,” said Agah.
The system’s reliability was also impressive. Results were found to be highly repeatable with less than 10 percent variations, and no deterioration of the detector excitation electrodes was observed after 12 hours of continuous operation.