Sigma-Aldrich Lecture in Materials Chemistry

"Carbon Nanotubes Chemiresistors for Biological and Agricultural Applications"

Carbon nanotube networks represent a powerful platform for the generation of chemiresistive sensors. Through the selective chemical functionalization with selector molecules and/or receptors, the conductance can be made selective to the presence of analytes ranging from large biological macromolecules to small gaseous molecules. This lecture will detail the fabrication of robust sensors using new functionalization chemistry to impart selectivity to the carbon nanotubes and methods to minimize drift that is often inherent in resistivity-based sensing schemes.  Sensor arrays with low levels of cross-reactivity between sensor elements will be discussed for the robust classification of chemicals. The use of carbon nanotube-based gas sensors for the detection of ethylene and other gases relevant to the monitoring fruit and produce ripeness will be presented. Gas sensors for agricultural and food production/storage/transportation are being specifically targeted and can be used to create systems that increase production, manage inventories, and minimize losses.

About Timothy Swager

Timothy M. Swager is the John D. MacArthur Professor of Chemistry at the Massachusetts Institute of Technology. A native of Montana, he received a BS from Montana State University in 1983 and a Ph.D. from the California Institute of Technology in 1988. After a postdoctoral appointment at MIT he was on the chemistry faculty at the University of Pennsylvania and returned to MIT in of 1996 as a Professor of Chemistry and served as the Head of Chemistry from 2005-2010. He has published more than 300 peer-reviewed papers and more than 50 issued/pending patents. Swager’s honors include: The John Scott Award, Election to the National Academy of Sciences, an Honorary Doctorate from Montana State University, the Lemelson-MIT Award for Invention and Innovation, Election to the American Academy of Arts and Sciences, the Christopher Columbus Foundation Homeland Security Award, and The Carl S. Marvel Creative Polymer Chemistry Award (ACS).

Swager’s research interests are in design, synthesis, and study of organic-based electronic, sensory, high-strength and liquid crystalline materials. His liquid crystal designs demonstrated shape complementarity to generate specific interactions between molecules and includes fundamental mechanisms for increasing liquid crystal order by a new mechanism referred to as minimization of free volume. Swager’s research in electronic polymers has been mainly directed at the demonstration of new conceptual approaches to the construction of sensory materials. These methods are the basis of the Fido^TM explosives detectors (FLIR Systems Inc), which have the highest sensitivity of any explosives sensor.   Other areas actively investigated by the Swager group include radicals for dynamic nuclear polarization, applications of nano-carbon materials, organic photovoltaic materials, polymer actuators, and luminescent molecular probes for medical diagnostics. He is the cofounder of 3 companies and has served on a number of corporate and government boards.