- SPECIAL REPORTS
The Virginia Polytechnic Institute is located less than 100 miles from Steele’s Tavern, VA, site of the first successful demonstration of a mechanized agricultural implement in 1831. Cyrus McCormick’s reaper revolutionized farming in the 19th century. Today, engineers at Virginia Tech are busy working on another type of harvesting that may revolutionize consumer electronics and other industries.
Batteries take up valuable space, add weight and provide limited robustness. In the future, many manufacturers plan to replace batteries with energy harvesting technology-a cost-effective process of converting freely available energy into electricity.
“Unused power exists in various forms, such as industrial machines, human activity, vehicles, vibrating structures and other environmental sources,” says Shashank Priya, an associate professor of mechanical engineering and material science. “Ambient, unused energy around us, just waiting to be harvested, is continually transmitted by various sources, such as radio and television towers, satellites, cellular phone antennas and portable electronics.”
Priya and his colleagues hope to tap into the vast amounts of light, thermal, mechanical, wind, acoustic and chemical energy that is wasted every day. That’s why they created the Center for Energy Harvesting Materials and Systems (CEHMS) two years ago. It is the only facility of its type in the United States.
“Demand for energy harvesting products has been increasing, but industry has been unable to meet the product requirements, thus delaying the launch of this vital sector,” says Priya, who serves as CEHMS associate director. “At the same time, new applications have emerged, creating [a need] to discover novel materials and conversion mechanisms, and to invent micro-to-macro scale components and systems.”
The CEHMS, a collaborative effort between academia (Virginia Tech is the lead school, working with the University of Texas at Dallas) and industry, was formed to address these critical needs. Priya believes the organization’s R&D efforts will spawn a new generation of products and industries. Smart homes, smart highways, cell phones, music players, radar, GPS and automobiles are a few areas that will directly benefit from CEHMS achievements.
“Our vision is to . . . provide comprehensive expertise in all aspects [of energy harvesting], including materials, components, system design, analysis, characterization and prototyping,” Priya points out. “Our mission is to provide integrated solutions to microelectronic, mobile and wireless technology problems through modeling, analysis, fabrication and demonstration of intelligent systems.”
The Virginia Tech engineers are also developing the architecture for “self-powered sensors” and opening the pathway for distributed power sources. Priya says they plan to “demonstrate harvesters utilizing single and multimodal conversion mechanisms, adaptive energy harvesting circuits, intelligent energy management systems and conformal storage media.”
Fourteen Virginia Tech faculty members from the College of Engineering and College of Science are currently involved in CEHMS research involving both civilian and defense applications. For instance, they’re working on aircraft structural health monitoring, bridge health monitoring, cell phone recharging, human body energy harvesting and ocean wave energy harvesting. Other activities involve replacing wiring for sensors and actuators with wireless devices that generate their own electricity.
“Currently, the focus is on full system design, where we try to integrate all the components- harvester, electronics, storage and wireless sensor node-within the given constraints,” says Priya. “Each of these components always should have high efficiency.”
The CEHMS hosts an annual meeting that attracts a wide variety of energy harvesting experts. This year’s event will be held Aug. 7-11 in Roanoke, VA. To learn more, call 540-231-2908 or click http://cehms.mse.vt.edu.