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Using Lasers to Develop Sensors
Using Lasers to Develop Sensors - Columbian College of Arts and Sciences

Oct 09 2009

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J. Houston Miller spends hours with his team working on spectroscopy research in the basement of Corcoran Hall, using beams of light to determine the presence of substances within flames and in other samples.

Miller has refined a procedure using the cavity ring down technique, in which a laser beam bouncing between mirrors can provide sensitive and precise measurements of the presence of molecules within a sample. The method can be used to develop sensors, and a Pennsylvania company is using Miller’s system in a commercial atmospheric device.

“We developed equipment based on this testing strategy and developed software to analyze the signals, to do the statistics,” said Miller, a chemistry professor in the Columbian College.

Sensors have wide commercial potential. Pipeline companies, for example, might need to know about impurities in natural gas. Such sensors could be used in monitoring indoor air quality and in fire detection, as noted in a recent paper published by Miller and graduate student Eric Fallows. Developing gas sensors is just a part of Miller's research; for example, he has also studied the use of gold or silver nanoparticles as sensors for medical diagnostics.

“Being able to see what you’re doing in the lab brought to the market, that has a lot of value,” Miller said.

New Research on Biofuels

Miller is also turning his efforts to the fuel industry as part of a team of scientists, engineers and businesses growing algae for the production of biofuels, a promising but problematic area for researchers.

Biofuels have been praised and pannedóbiofuel crops can re-absorb emissions produced by engines but planting biofuel crops can divert land from the food supply. However, cropland is not needed to grow algae and can be produced in a carbon dioxide-rich environment, perhaps next to a power plant, explained Miller.

The military is interested in biofuels, but is concerned because fuel on bases may be stored for long periods, where it can degrade. Air transportation and heavy trucks will also always require energy-dense fuel to move cargo. In addition, biofuel can fill a niche for high-density liquid fuel. 

Biofuels, however, can still pollute the air. For example, biofuel exhaust can contain formaldehyde, an airborne carcinogen. “But what if there are some slight tweaks you can do to the fuel to minimize the presence of formaldehyde?” Miller speculated. Part of his research also focuses on measuring gases released during algae growth to look for emissions that correlate with desirable biofuel properties, like yield of lipids.

Said Miller about his research and its potential impact:  “It’s Christmas every day. I get to play with amazing toys. I have amazing access to technology. And I get to work with smart and energetic collaborators at GW and around the world.”