New De-icing Technology

CONTACT: Catharine Lamm
603/646-3943

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 Dartmouth Engineering Professor Victor F. Petrenko has found a way not only to modify ice's adhesion to a variety of materials, but also to keep ice from forming in the first place.

Petrenko's patented inventions, involving four different ice-manipulating methods, use low-voltage electricity to remove ice, prevent it from forming, or either increase or decrease ice-surface friction. Ice can be made simply to fall off an airplane wing, and the day may come when car tires get 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% 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 twenty 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 three licenses covering specific applications of the technology. The BFGoodrich Company (now Goodrich Corporation) holds a license for aerospace and marine applications, Torvec, Inc. will develop the technology for land-based vehicle applications, and Advanced Recycling Sciences, Inc. (ARS) plans to commercialize the ground-surface applications. Other companies have also expressed strong interest, including New York Power Authority which is supporting Petrenko's development of a prototype de-icer for power lines.

BFGoodrich acquired its license in January, 2000. "In our preliminary testing of Professor Petrenko's technology, we were able to achieve zero ice adhesion. The ice literally fell off the test component," said Dr. Stan Prybyla, a Senior R&D Associate from BFGoodrich Aerospace. Current airplane de-icing methods employ decades-old technology. "We are now looking to develop a novel low-power de-icing system that is robust to the operating environment and readily manufacturable. The program to develop the Dartmouth technology is moving forward very nicely. We have demonstrated our proof of concept, and we plan to build and test a sub-scale prototype by the end of 2001." BFGoodrich is headquartered in Charlotte, North Carolina. Its aerospace segment is one of the world's leading suppliers of components, systems, and services to the aerospace industry. Assisting in Petrenko's joint project with BFGoodrich are Dr. Lev Deresh, Thayer School visiting research scientist, and Zoe Courville, Thayer School Ph.D. candidate.

Then in November, 2000, Dartmouth and UTEK Corporation—a business development company dedicated to building bridges between university developed technology and commercial organizations—announced jointly that the Dartmouth Trustees had granted a worldwide exclusive license to Ice Surface Development, Inc. (ISDI), a subsidiary of UTEK, for Petrenko's ice adhesion modification system for land-based vehicle applications. ISDI was subsequently acquired by Torvec, Inc., a Rochester, New York-based developer of advanced automotive technologies. In addition to integrating Petrenko's inventions into Torvec's "Fast Tracked Vehicle," ISDI plans to develop a marketable non-thermal windshield de-icer, which would prevent ice from even forming, and further develop Petrenko's "Electrostatic IceBraker" traction system which works by inducing an electric field strong enough to significantly increase the friction between tires and ice. "There's nothing like a 60-ton tank slithering around on the ice to make you think Professor Petrenko's technology is a good idea!" said Dr. Herbert H. Dobbs, Chairman of the Board of Directors of Torvec. "This is a new direction for Torvec. Up to this point we've used only our own technology. But we think this has enormous potential." Mikhail Starostin, a Thayer School visiting professor from Russia, is helping Petrenko to develop a prototype of the windshield de-icer, while Masahiko Arakawa, a visiting professor from Japan, is working on the ice-traction system. In the future, both technologies may well be available as options on new cars—like a sunroof or a CD player. The traction system could also be used for shoes, requiring only a simple ice sensor and a small battery.

Most recently, in February, Dartmouth and UTEK made another joint announcement that the Dartmouth Trustees granted a worldwide exclusive license for the ground surface applications of Petrenko's de-icer to Technology Development, Inc.(TDI), another subsidiary of UTEK. TDI was subsequently sold by UTEK to ARS. ARS, through its new TDI subsidiary, plans to commercialize the technology for use in motor vehicle roadways, bridges, and tunnels; airport runways, taxiways, and tarmacs; pedestrian walkways; sports facilities and playgrounds; and for indoor and outdoor floors and ground covering systems. "I have a vision of an overhead picture of a major international airport in the middle of winter, and all around the airport is white, except for the runway which is perfectly black," said John Pope, Vice-President of Finance for ARS.

For these ground surface applications, low-voltage electricity is distributed either through a metal grid embedded in the surface or by using electrically-conductive paint. A visiting scientist from Japan, Michiya Higa, is joining Petrenko's team to help further develop this ground-surface de-icing technology.

ARS, based in California, is striving to establish itself as a leader in the development of environmental technologies and crumb-rubber modified asphalt technologies.

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 on 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 embedded in a coating applied 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 cheapest and most primitive method," says Petrenko, but salt has a corrosive effect on many materials. Organic liquids, such as the antifreeze in cars, are 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; indeed, a single plane can require up to 10 treatments in one day.

Last year, Petrenko's airplane de-icer was the winner of the 2000 Discover Award for Technological Innovation for the aerospace category.

As for keeping ice off power lines, Petrenko has been working with assistant professor Charlie Sullivan, graduate student Josh McCurdy, and research engineer Alexander Rtishchev to develop a prototype transmission line de-icer. "Power lines produce their own electric field," says Petrenko, "which can be adjusted to produce enough heat for a de-icing effect." This is good news, considering that the ice storm of 1998 in New England alone cost over $5 billion, mostly from damage to power lines.

Overall, ice takes a major toll on society—airplanes downed, grounded, or rerouted, car accidents on icy roads and bridges, power outages, ships capsizedso 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 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!"