Meet Sumit Gangwal

Sumit Gangwal
Sumit Gangwal



































Earning him the first-place award in the Engineering category of this spring’s Graduate Student Research Symposium, Sumit Gangwal’s winning research poster was entitled, “Dielectrophoretic and electrokinetic behavior of ‘Janus’ particles in AC electric fields.”

Gangwal grew up in Durham, NC, and completed his bachelor of science in Chemical Engineering at NC State in 1997. After working for IBM and Eastman Chemical Company, Gangwal, a doctoral student in chemical and biomolecular engineering, said he decided to return to NC State in 2005 to pursue graduate school. He made the decision both because of the NC State’s program in chemical and biomolecular and his wife.

“My wife and I started graduate school at NC State together so that is part of the reason why I came back here for grad school,” he said. “After the first year of graduate school, I was thinking about just completing my Masters, but I enjoyed my research work and ultimately decided to go for the Ph.D.”

Gangwal’s doctoral research is focused in colloid nanoscience and engineering, specifically “the application of alternating current (AC) electric fields on very small, spherical particles having one-half surface that is conductive and the other half surface that is insulating.” These particles, which are approximately five micrometers in diameter or about one-tenth the thickness of a human hair, are called “Janus” particles because of their dual electrical surface properties.

“The so-called ‘Janus’ microspheres are named after the Roman mythological god Janus, who possessed two faces,” Gangwal said. “The particles are suspended in water and electric fields are applied to the particle-water suspension.”

Gangwal also found that high frequency AC electric fields applied to the Janus particles form novel types of staggered chains and three-dimensional bundle structures.

“Very few researchers have applied external fields to [dual-surface] anisotropic particles in order to assemble them into new structures,” Gangwal said. “I have attempted to form new two-dimensional structured materials comprised of the Janus particles.”

Of his findings, Gangwal said two items stand out in particular.

“When low frequency AC electric fields are applied to the Janus particles, the particles move perpendicular to the electric field direction by induced-charge electrophoresis due to unbalanced liquid flows around each half of the particle,” he said, adding that while these results have been previously predicted in theory, they have not yet been demonstrated in experimentation.

“Where they align, … the metal patch touches the metal patch of an adjacent particle and the dielectric insulting half alternates on either side not in contact with anything,” he said.

While the field of colloid nanoscience and engineering may not be familiar to all, Gangwal stressed the importance of making research information accessible. Through previous poster presentations at the 2008 Graduate Research Symposium and technical conferences for the American Chemical Society (ACS) Colloid and Surface Science, he said he has learned the importance of summarizing and consolidating research in a concise manner in order to better share it with the public and even fellow researchers.

“It is most important to know your audience and to explain your research at a high level so that your audience fully understands and appreciates what you are talking about,” Gangwal said. “I learned from last year at the Symposium that practicing a two-minute talk … and being able to go through the entire poster in this short time is very important.”

In fact, Gangwal suggests that stepping back and taking perspective on the research can make all the difference.

“I am all for the ability to simplify you research so that you can explain your work to a fifth grade student,” he said.

When not researching or presenting interesting findings, Gangwal said he enjoys outdoor activities and spending time with his family, including his wife and daughter.

“I like to play tennis, ski, go camping [and] hike,” he said. “I have a 22-month-old daughter that keeps my wife and me quite busy.”

Gangwal plans to graduate in fall 2009.

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