University of Texas at Dallas researchers and their colleagues at other institutions are investigating ways to harvest energy from such diverse sources as mechanical vibrations, wasted heat, radio waves, light and even movements of the human body.
The goal is to develop ways to convert this unused energy into a form that can self-power the next generation of electronics, eliminating or reducing the need for bulky, limited-life batteries.
Beyond the more familiar wind and solar power, energy harvesting has a wide range of potential applications. These include: powering wireless sensor networks placed in “intelligent” buildings, or in hard-to-reach or dangerous areas; monitoring the structural health of aircraft; and biomedical implants that might transmit health data to your doctor or treat a chronic condition.
At a recent scientific conference held at UT Dallas, experts from academia, industry and government labs gathered to share their latest research on energy harvesting. Energy Summit 2013 focused on research initiatives at UT Dallas, Virginia Tech and Leibniz University in Germany, which form a consortium called the Center for Energy Harvesting Materials and Systems (CEHMS).
Founded in 2010, CEHMS is an Industry/University Cooperative Research Center funded in part by the National Science Foundation. It includes not only academic institutions, but also corporate members who collaborate on research projects and also provide funding for the center. Roger Nessen, manager of sales and marketing at Exelis Inc. is chairman of the CEHMS advisory board.
“The CEHMS consortium is a diverse group with expertise at all levels, from fundamental chemistry and materials science, to developing new models and fabrication techniques, to working on product-centered areas,” said Dr. Dennis Smith, co-director of CEHMS and the Robert A. Welch Distinguished Chair in Chemistry at UT Dallas.
“Developing energy-harvesting technology is a necessary step toward more widespread use of wireless sensor networks, and will enable new types of self-powered applications. Being a member of this consortium provides great benefit and opportunities to UT Dallas researchers and students, as well as local companies.”
The two-day Energy Summit covered a wide range of topics, including projects from laboratories in UT Dallas’ School of Natural Sciences and Mathematics and the Erik Jonsson School of Engineering and Computer Science.
For example, Dr. Mario Rotea, the Erik Jonsson Chair and head of the Department of Mechanical Engineering at UT Dallas, discussed some of his work aimed at advancing the development of wind energy systems. He represents UT Dallas in a proposed new consortium of universities and companies called WindSTAR that would collaborate with CEHMS on wind energy science and technology issues.
Dr. Dennis Smith
On the chemistry front, Smith’s synthetic chemistry lab is working with advanced materials that use piezoelectrics. If a piezoelectric material is deformed by a mechanical stress – such as stepping on it or subjecting it to vibrations – it produces an electric current. Smith’s lab is investigating whether the addition of nanoparticles to certain piezoelectric materials can boost this so-called piezoelectric effect.
CEHMS co-director Dr. Shashank Priya, professor of mechanical engineering and the James and Elizabeth Turner Fellow of Engineering at Virginia Tech, collaborates with Smith on piezoelectric research. Among many projects, researchers at Virginia Tech are incorporating piezoelectrics into “smart” tiles that produce electricity when stepped upon, as well as into materials that might be applied like wallpaper to gather light and vibrational energy from walls.
Other university and industry projects include:
Investigating how to redesign systems to require less power.
An intelligent tire system that harvests energy from the vibrations in a rotating tire, powering embedded sensors that gather and report data on tire pressure, tire conditions and road conditions.
A new class of magnetoelectric materials that can simultaneously convert magnetic fields and vibrations into energy.
A textile-type material that converts wasted thermal energy into electricity, which could be wrapped around hot pipes or auto exhaust pipes to generate power.
Flexible solar cells that could be integrated into textiles, and worn by hikers or soldiers to power portable electronic devices far away from an electric socket.
Dr. Walter Voit, assistant professor of materials science and engineering at UT Dallas, is investigating biomedical applications for energy harvested from sources such as radio waves or blood flow. He has developed a novel material called a shape memory polymer that shows promise for remaining in the body for long periods of time without producing scar tissue or promoting infection – but to exploit those properties in new devices, he needs power.
“Researchers in energy harvesting, flexible electronics and biomedical devices can really learn a lot from one another and build off one another,” Voit said. “The key to the next generation of these devices is solving the power issue. Here in Dallas with the electronics industry and UT Southwestern Medical Center down the street, we have a real opportunity to build off the materials work we're doing here, as well as the design and modeling work that's going on at Virginia Tech, to really solve some of these power problems and translate that into devices that will help patients.”
Energy Summit 2013 also held a research poster competition, which highlighted two dozen projects from CEHMS institutions. Judges awarded first place and $200 to a poster from a UT Dallas group led by Erika Fuentes-Fernandez, a graduate student in materials science and engineering. The project involved the synthesis and characterization of piezoelectric materials for use in thin-film cantilevers that might be used in energy harvesting.