Dartmouth Engineer - The Magazine of Thayer School of EngineeringDartmouth Engineer - The Magazine of Thayer School of Engineering

Lab Reports

More Power, Less Money

Charles Sullivan
Charles Sullivan

Thayer Professor Charles Sullivan is working to improve the performance of passive high-frequency power components in order to make power electronics more energy efficient and cheaper to manufacture.

According to Sullivan, the passive components are often the limiting factors in improving the efficiency and lowering the cost of high-frequency electronic power converters. His research targets inefficiencies in the inductors, transformers, and capacitors that handle AC-DC, frequency, and voltage conversions required by electronic devices. For example, the power adaptors that laptop computers use to convert 120-volt AC power to lower voltage DC power lose considerable energy in the form of heat.

High-frequency electronic power converters are often problematic due to their size and weight, says Sullivan. Designers, he says, generally know how to make high-frequency power converters more efficient, but the results can be unwieldy and prohibitively expensive. Thus, efficiency often is sacrificed to make converters affordable. Sullivan maintains that innovation in both the application of new materials and the geometric configuration of circuits will improve the performance and cost of passive power components.

He sees advances in information technology as both a model and means for improving power electronics. “Electronic information handling has made it possible to access efficiently exactly the information we need,” he says. Applying similar techniques to energy processing would “similarly allow us to use exactly the energy we need where and when we need it, with less waste,” he says. “Our goal is to make designing power electronics as easy as designing information electronics, so that we can see the same rapid advances in energy applications as we’ve seen in information applications.”
— Elisabeth McDonnell ’08

Pollution-Detecting Molecules

Thayer Professor Ursula Gibson ’76 and researchers at the University of New Hampshire are collaborating on a new method of monitoring watershed pollution: using molecularly imprinted polymers to detect contaminant molecules. Designed to recognize organic solvents, the polymer films can target a pollutant and generate a signal based on its concentration. An array of such sensors could be used to detect spills and locate their sources.

Gibson’s team is currently developing the polymer coatings and investigating how to arrange them in the most sensitive configuration. Once they accomplish this, they will work on integrating specific coatings into an autonomous sensor package capable of identifying pollutants and reporting their levels for extended periods.
— E.M.

Advances in Ethanol

The nation’s thirst for gasoline alternatives is driving new rounds of investment in Mascoma Corp., the cellulosic biofuel company co-founded in 2005 by Thayer Professors Lee Lynd Th’84 and Charles Wyman. The three-year-old startup recently reached $100 million in equity investment and received commitments for another $100 million in state and federal grants, including a $26-million grant from the U.S. Department of Energy.

Using proprietary microorganisms developed at the company’s laboratories in Lebanon, N.H., Mascoma is pioneering new ways to turn non-food, renewable biomass — including wood, straw, switchgrass, paper pulp, and agricultural wastes — into ethanol and other biofuels. Lynd, recipient of the first Lemelson-MIT Award for Sustainability in 2007, is championing a single-step process for converting cellulose to ethanol — he calls it Consolidated Bioprocessing (CBP) — that is designed to be faster, cheaper, and more efficient than current methods. Mascoma is testing its CBP technology and expects to begin ethanol production later this year at the demonstration plant it is constructing in Rome, N.Y.

Investors in Mascoma, whose corporate office is in Boston, now include Marathon Oil Corp., General Motors, Khosla Ventures, Flagship Ventures, Atlas Venture, General Catalyst Partners, Kleiner Perkins Caufield & Byers, Pinnacle Ventures, and Vantage Point Venture Partners.

For Lynd’s views on the viability of cellulosic ethanol as an alternative to corn-based ethanol, read Answers to the Growing Fuel Debate.

For more photos, visit our Energy Technologies and Sustainability page and Research and Innovations page on Flickr.

Categories: The Great Hall, Lab Reports

Tags: award, complex systems, energy, entrepreneurship, faculty, research

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