Ice buildup meets its match in Dartmouth professor's invention

Posted 01/03/01

Imagine never having to scrape your windshield again or defrost your freezer; imagine never again having to worry about ice buildup on an airplane wing, or that a highway bridge might be icy; and imagine that roofs and power lines could be kept permanently free of ice.

It could become reality in the near future because Victor F. Petrenko, Professor of Engineering at Dartmouth's Thayer School of Engineering has found a way to not only remove ice from a variety of materials, but to keep ice from forming in the first place.

Petrenko's patented inventions, involving four different ice-manipulating methods, use low-voltage electricity to not only quickly, cheaply, and effectively remove ice and prevent it from forming, but also to modify its stickiness. Ice can be made to simply fall off an airplane wing, or the day may come when a little switch in our cars can give tires the same traction on ice that they would have on dry pavement.

"Ice adheres to anything, and it's ubiquitous," Petrenko said, "Its properties make life possible, but it often gets in the way. Our approach differs from 99 percent of other attempts to solve the ice adhesion problem. Most efforts have tried to shortcut around basic research through simple trial and error. Millions and millions and millions of dollars have been wasted on this approach in just the last couple of decades. In contrast, I have spent the last 20 years gaining a basic understanding of ice-surface physics and engineering, and it's taken me seven years to apply that basic knowledge and begin to develop the technologies needed to solve the problems of ice adhesion."

Dartmouth has already granted two licenses covering specific applications of the technology to BFGoodrich and UTEK Corporation, Inc., and several others are expressing strong interest, including New York Power Authority, who is supporting Petrenko's development of a prototype de-icer for power lines.

In January 2000, BFGoodrich, a leader in the development and manufacturing of de-icing devices in the aerospace industry, acquired its license and exclusive rights to Petrenko's de-icing technology for aerospace and marine applications. (BFGoodrich sold its car tire division to Michelin; it is now a high-tech company that makes, for example, most of the space-shuttle hardware. Together with Thayer School, BFGoodrich is developing a flying prototype de-icer. "This is precisely the type of development that we seek to encourage. It represents a major potential breakthrough not simply an incremental improvement," said Jerry Lee, Senior Vice President of Technology and Innovation at BFGoodrich.

UTEK and Dartmouth announced jointly in November that the Dartmouth Trustees granted a worldwide exclusive license to Ice Surface Development, Inc. (ISDI), a subsidiary of UTEK Corporation, to Petrenko's ice adhesion modification system for land-based vehicle applications. With this license, ISDI plans to develop a marketable windshield de-icer as well as Petrenko's ice-traction system that works by inducing an electric field strong enough to significantly increase the friction between tires and ice. This means that ISDI may someday be the supplier of a windshield de-icer and ice traction system, both perhaps available as options on new cars just like a sunroof of a CD player is today.

Any royalties from Petrenko's inventions will benefit both Dartmouth and Thayer School as well as Petrenko and his research team.

Ice's notorious stickiness comes from its charged surface, which induces an opposite charge from the surface to which it adheres. The natural attraction between the opposite charges is what makes ice so hard to remove. One of Petrenko's inventions involves sending an electric current across the ice-material interface. In the case of de-icing airplanes, electrodes attached directly to aircraft surfaces would break down ice as it forms through the process of electrolysis, transforming ice directly into hydrogen and oxygen gases. If any ice buildup does occur-which can happen if a large amount of moisture is hitting the plane-bubbles forming at the ice-metal interface generate pressure and literally push the ice off the surface. This same principle can work for ships, cars and trucks, windshields, offshore structures, roads and bridges, ski lifts, roofs, and the inside of a freezer.

This new technology has generated a lot of excitement because there is so much room for improvement on current de-icing methods. "Salt is the most cheap and primitive method," says Petrenko, but salt has a corrosive effect on many materials. Then there are organic liquids, like the antifreeze in cars, which is environmentally unfriendly, expensive, and short-lived. Treating the wings of a plane with antifreeze costs about $3,000 and is only effective for a few minutes so that a single plane can require up to 10 treatments in one day.

This year, Petrenko's airplane de-icer was the winner of an 11th Annual Discover Award for Technological Innovation for the aerospace category.

As for keeping ice off power lines, "they produce their own electric field which can be adjusted to produce enough heat for a de-icing effect," he said. This is good news considering the ice storm of 1998 in New England alone cost more than $5 billion, mostly from damage to power lines.

Overall, ice constitutes a major toll on society-airplanes downed, grounded, or rerouted, car accidents on icy roads and bridges, power outages, ships capsized-so much so that it's difficult to quantify. "It's all very exciting and is keeping me very busy!" says Petrenko, "The Army Research Office (ARO) was the first to recognize that an investment in basic research was the place to start to solve this problem. Soon after, the National Science Foundation added its support, and that approach has worked very well!"