Professor looks for power in polymers

ShareThis

PITTSBURGH -- There are 3.5 million miles of rivers in the United States.In Lisa Mauck Weiland's dreams, they could be the next great clean energy source for the world, but not the old-fashioned way, with dams and hydroelectric power plants.Instead, Weiland, a mechanical engineering professor at the University of Pittsburgh, hopes to use tiny strips of plastic, undulating in the current of rivers and streams, to produce electricity.An expert in "smart materials," Weiland and her team at Pitt are working on a project in which they hope to use plastics known as ionic polymers to help generate electricity for the town of Vandergrift in Westmoreland County, 25 miles northeast of Pittsburgh.If her plans work out, the borough's historic downtown could one day get 20 percent or more of its electrical power from a mile-long array of tiny plastic devices wiggling away on the bottom of the Kiskiminetas River as it sweeps around the town.Ionic polymers, already used as sensors, have the ability to dynamically generate current when they move, and Weiland and her engineering students are now trying to figure out the best size, shape and array of the plastics to put in the Kiski River sometime in the next five years.Once the array goes in on the riverbed, she said, "if you were able to look at it, you would just see a bunch of little things wiggling. It wouldn't look that different from a bunch of plant life." Cables from the array might then connect to the town's power grid at different spots along the bank.The power generation project is just one part of the Vandergrift Improvement Program, in which the borough, designed in 1894 as a model steelmaking community, now hopes to revitalize itself as a model "green" community, with the help of Pitt, the Pittsburgh History & Landmarks Foundation and the state Department of Community and Economic Development.Weiland is Pitt's key liaison to the project, and she plans to put as much energy into community education work on environmental sustainability as she does on the power experiment.By working with Vandergrift's citizens on conserving energy and developing clean technologies like solar power, she said it's conceivable downtown Pittsburgh could one day function without using any fossil fuels.The residents' creativity and ideas will be crucial to the effort, she said, because even though "technology is going to have a very important role to play, technology alone is not going to come to the rescue. It took all of us to make this mess and it will take all of us to clean it up."While the Vandergrift project has become Weiland's personal mission, it is not her professional passion.That is planes, and specifically, changing the shape of military aircraft in midflight, a process known as morphing.The idea behind this experimental work is to develop an aircraft that can perform more than one function. Right now, for instance, if a fixed-wing military surveillance plane spots some trouble from high altitude, it has to signal for other planes to investigate, and by that time, it might be too late.But what if the surveillance plane could change the shape and angle of its wings and go down to eyeball the situation itself? That's the idea behind morphing, she said.Engineers have made great strides in figuring out how to change the shape and angle of the wings in midair, she said, but haven't licked the problem of how to get the craft's skin to alter itself. "The skin is one of the last hurdles to developing an airplane that can morph in flight, just like a bird does," Weiland said.The trick is to find a material that can soften when the wings are changing shape and then harden again. There is one class of materials that can be softened with heat and then regain its rigidity, but that process is too slow and could give off a "heat signature" that the enemy could detect, she said.As an alternative, her lab is investigating materials that could soften and reharden after exposure to different wavelengths of light, or different electrical frequencies.E-mail Mark Roth at mroth(at)post-gazette.com.(Distributed by Scripps Howard News Service, www.scrippsnews.com.)