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 A research team led by George C. Hadjipanayis, Richard B. Murray Professor of Physics at the University of Delaware, has been awarded a $4.27 million grant by the Defense Sciences Office of the federal Defense Advanced Research Projects Agency to develop novel magnetic meta materials.
Meta materials are artificially constructed materials that exhibit responses not found in nature. The UD-led team is working to develop new classes of meta materials with previously unattainable low frequency magnetic properties and to integrate those materials into device prototypes that will enable new and enhanced capabilities for the military and for commercial development with great energy savings.
The research at UD will involve both permanent magnets and soft magnetic materials. In permanent magnets, research will be focused on nanocomposite magnets consisting of a fine mixture of magnetically hard and soft phases with a grain size of about 10-20 nanometers. For a sense of scale, one nanometer equals one one-thousandth of a micron and one micron equals one one-thousandth of a millimeter.
In soft magnets, research will be focused on fiber reinforced cobalt iron alloys with negligible creep at high temperatures and on artificially made ferrites.
The new hard and soft magnets to be discovered will allow the development of more electric airplanes for the U.S. Air Force and also of unmanned underwater vehicles and torpedoes.
Additionally, high performance permanent magnets could enable electric drives for tanks and automobiles, quieter and more efficient electric motors and bearings for lubrication-free motors and generators.
Meta materials also offer promising opportunities for future applications, including new solutions to antenna proliferation and radio frequency interference, open magnetic resonance imaging (MRI), faster spindle motors for computer hard drives, and wireless power transfer.
Another $1.5 million could be made available to the research group, contingent upon the research progress and team performance and the availability of government funds.
The University of Delaware team, led by Hadjipanayis, includes Karl M. Unruh, John Q. Xiao and Sui-Tat Chui. Also included are scientists from Carnegie Mellon University, the Naval Research Laboratory, NanoPac Inc., Electron Energy Corp., Materials Modifications Inc. and Advanced Ceramic Research.
According to Valerie Browning, who directs the DARPA meta materials program, the physics of conventional bulk materials, and the design constraints associated with them, limit their ultimate performance. Due to a new “small-scale” physics associated with their engineering, meta materials exhibit superior properties and enhanced performance.
The “small-scale” physics occurs when the size of the composite becomes of the same order as the characteristic length of the physical property. For magnets, this is the domain wall thickness.
The new class of engineered nanocomposites, or meta materials, has been made possible through the development of novel synthesis concepts in recent years.
The aim of meta materials development is to engineer unit cell building blocks that have dimensions commensurate with small-scale physics and to assemble these building blocks into three-dimensional, large-scale bulk materials while still preserving their unique and superior properties.
The goal of the four-year UD program is to develop and demonstrate novel meta materials by controlling and manipulating the material properties at the nanoscale. The new magnetic materials to be developed will afford new and enhanced capabilities for a number of crucial military applications.
Browning said DARPA will continue to invest in research and technology development that supports the military’s long-term capability goals.
Story by Neil Thomas
Photographs by Kathy Flickinger
March 11, 2002
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