Four UD faculty members, two from the College of Engineering and two from the College of Arts and Sciences, were awarded the 2004 National Science Foundation (NSF) prestigious Faculty Early Career Development Award. Darrin Pochan, assistant professor of materials science and engineering, Joel Schneider, assistant professor of chemistry and biochemistry, Chien-Chung Shen, assistant professor of computer and information sciences, and Daniel Weile, assistant professor of electrical and computer engineering, received the NSF award, which recognizes and supports the early career development activities of "those teacher-scholars who are most likely to become the academic leaders of the 21st Century." Recipients are selected based on creative plans that effectively integrate research and education. The five-year award includes research funds of $400,000.
A new approach to electromagnetic equations
Daniel S. Weile, assistant professor of electrical and computer engineering, is seeking a missing link in computational electromagnetics.
His NSF award will support Weile's research on a new computational electromagnetics technique, called Accurate Marching by Band-Limited Extrapolation, or AMBLE, that could help in the design of modern communications systems.
"Prof. Weile's research focuses on computational electromagnetics, which is of importance in many areas of electrical and computer engineering, including communications, sensors, semiconductor design, smart-materials and nanotechnology," Gonzalo Arce, chairperson of UD's Department of Electrical and Computer Engineering, says. "This award will significantly accelerate his research contributions and will provide him with a mechanism to broadly integrate his research activities into our undergraduate programs.
"The NSF award is competitive and is a good indicator of the quality and potential of young investigators."
Weile says the focus of his research is on developing a new method for doing computational electromagnetics. Currently, three methods are in use, but he says logic would suggest that there should be four, given that there are two types of equations (integral and differential) and two domains (frequency and time).
However, for the last three decades, researchers have avoided the fourth method, the time-domain integral equation, because it has proved to be extremely problematic. "This method has never worked," Weile says. "It has been unstable, and no one could ever figure out why. It tended to accumulate errors that washed out the solutions to the equations, so it was utterly useless. It didn't even give an approximation of a sound answer.
"We believe we have found the core problem as to why it was unstable in the first place, and we think we've found a way to solve the problem."
The value of the research, he says, is that AMBLE can be used to tackle many of the outstanding problems in electromagnetics for which the other three methods of computation are unsuitable.
Once a code is developed, it could be particularly useful for modeling cellular telephone systems. "You will be able to better simulate the system, since you will no longer have to assume the person using the phone is standing still," he says.
Weile says this is not the sort of project that will result in the creation of a specific product, but rather it is work that could provide other scientists the tools to enable the creation of thousands of products.
"At the end, what we hope to have is a very robust code," he says.
Weile developed an interest in electromagnetics as he began graduate studies at the University of Illinois at Urbana-Champaign. "I saw the field was taking a computational turn," he says. "It was taking a very mathematical approach to a physical problem."
Weile took a particular interest in the missing link of time-domain integral equations. "There was a gaping hole out there," he says. "I wondered why, after 30 years, no one had been able to make it work. It was a problem begging for a solution."
Weile has been on the UD faculty since August 2000.
Biopolymer research may produce bone-replacement material
Darrin Pochan, assistant professor of materials science and engineering, will use his NSF award to support his research on the use of biopolymers to construct advanced materials.
Pochan will study the feasibility of using biomolecules, namely synthetic polypeptides, as matrix materials for composite materials.
"There are two interesting twists in the work," he says. "The first is that by using biomolecules as the major component in the composite materials, one has the opportunity to produce new engineering or commodity materials--which could be something as mundane as plastic wrap or plastic parts in a device--or biomaterials--such as bone-replacement implants or burn healing films--with both the mechanical and biological properties of interest."
For example, Pochan says, the research could lead to the creation of a plastic film that can keep food fresh by limiting oxygen exposure and also can kill bacteria and biodegrade over a matter of weeks to months.
It also could lead to a bone replacement material that is inherently strong but can eventually erode in the body while encouraging the development of natural bone.
"The second twist," Pochan says, "is that the polypeptide materials will be filled with nanoscopically sized fillers to enhance the mechanical properties. The use of these fillers, including inorganic clays and self-assembled peptide fibrils, allows one to make a strong material even stronger by simply adding a little of the filler."
Essentially, he says, the overall properties of the nanocomposite material do not change but desired mechanical properties are enhanced. The plastic wrap, for example, would still be tough, elastic and optically transparent but, with the filler, would be even tougher and would keep oxygen out longer due to increased barrier properties.
"I am particularly excited about the fillers that are what we call self-assembled peptide fibrils," Pochan says. "This idea involves the use of a biological structure that in nature is associated with quite devastating diseases, such as Alzheimer's and Type II diabetes, and the ability to take advantage of the structure for materials properties."
When a person has Alzheimer's, large and stiff protein fibers are formed in the brain tissue due to natural proteins aggregating and not performing their natural function, Pochan says. Similar but benign fibers can be formed in the laboratory and then used as a filler in a composite.
"If one has a biomolecule matrix and fills it with the protein fibers, then a nanocomposite is produced that is completely made of biological molecules," he says. "These are especially promising as biocompatible, biodegradable, strong materials."
Pochan is conducting the research in collaboration with Joel Schneider, a UD assistant professor of chemistry and biochemistry, who also won an NSF Faculty Early Career Development Award recently. The Schneider group is helping with the design and synthesis of peptides for fiber formation to be used as fillers.
Pochan also is working with Timothy Deming, associate professor of materials and chemistry at the University of California Santa Barbara, to design and synthesize the polymeric peptide matrix materials.
"Darrin Pochan is an energetic, creative scientist and educator who represents a new breed of 21st-Century materials scientist," John Rabolt, chairperson of UD's Department of Materials Science and Engineering, says. "Both he and Kristi Kiick (also an assistant professor of materials science) work at the interface of established disciplines and will eventually eradicate the boundary between traditional materials science and chemistry, physics and biology. They continue to set an exceptionally high standard of excellence for young faculty in our department."
Mobile ad hoc networks a boom to communications
Chien-Chung Shen, assistant professor of computer and information sciences, is conducting research into mobile communication networks.
The NSF award will support Shen's research in developing mobile ad hoc communication networks, which, unlike cellular networks, have no
fixed stations to link communication devices.
M. Sandra Carberry, chairperson of the Department of Computer and Information Sciences, says Shen "is performing innovative research in wireless communication, particularly mobile and sensor networks. His work is leading the way to the next generation of computer networks, which will provide a much more flexible and robust computing environment than is available today.
"Moreover, he is incorporating these new technologies into his advanced courses, thereby enhancing the computer and information sciences graduate program. This very prestigious award recognizes excellence in young faculty and is a credit to Dr. Shen."
Anyone who has tried unsuccessfully to place a cellular telephone call from a remote mountain valley knows well the limitations of that type of network, which relies on stationary base stations. Mobile ad hoc networks, which are still under development, will not have to rely on such stations.
Mobile networks have special importance to the military for two key reasons. They do not rely on fixed stations, which can be destroyed, and they can provide links between individual soldiers and vehicles that are moving in many directions at once but still must be able to communicate.
Shen's research takes a new approach to mobile ad hoc networks. Traditionally, the mobility has been viewed as a problem, but he believes it can be viewed as an opportunity.
"If we can control the mobility, we can make it work to our advantage," Shen says. "It can become a first-class capability, not a second-class phenomenon."
In addition, the research is considering combinations of cellular and mobile networks and ways to extend capabilities by integrating communications, computing and control.
Shen says the research addresses both practical and theoretical problems, and he plans to integrate it into coursework.
A graduate of the University of California Los Angeles, Shen joined
the UD faculty in 1998 after working for Bell Communications Research, recently renamed Telcordia Technologies, in Piscataway, N.J.
Constructing biomaterials to replace human tissues
"You'll get a kick out of this" is how Joel Schneider, assistant professor of chemistry and biochemistry, introduces self-assembling peptides to an audience that has never taken even a high school chemistry class.
Schneider segues from layperson's lingo to postdoctoral parlance with aplomb. The NSF award will support his research on the construction of new biomaterials, an approach that could eventually be used to grow and replace human tissue.
Schneider also is the 2003 recipient of the Francis Alison Society's coveted and competitive Young Scholars Award.
Admirers call Schneider a natural mentor who can shift mental gears to teach anyone how his de novo peptide design research works. The professor's own take is much more modest: "I didn't start out breaking the information down for anyone else. I think I did it because I wasn't the sharpest knife in the drawer. I would have to explain things to myself so they made more sense. That's the God's honest truth."
This from a researcher whose work has been published nine times in the prestigious Journal of the American Chemical Society, who did his postdoctoral work with the leading international experts in his field and who, with several other UD assistant professors, has attracted more than $9.7 million in funding since he came to Delaware five years ago. He spoke at the 2003 Gordon Research Conference on Bioorganic Chemistry, where talking time is reserved for top scientists conducting innovative studies.
Scientists around the world are watching the collaborative research between Schneider and Darrin J. Pochan, assistant professor of materials science at UD.
Interested in the construction of new biomaterials, the two researchers design short segments of proteins called peptides so that they form responsive hydrogel materials--watery gels that form and dissolve in a predictable manner when exposed to light, heat or salt. The material's properties can be controlled at the molecular level by controlling the folding and self-assembly of these peptides.
Their peptide-based materials could someday be used as staging grounds to grow a patient's own tissue cells so they can be used to repair burned skin, or to grow bone cells for a patient with osteoporosis.
As Charles G. Riordan, chairperson of the Department of Chemistry and Biochemistry, says, "Joel's scientific background has positioned him to make important and lasting contributions to the field of bioorganic chemistry."
Despite the importance and complexity of his research--it takes a graduate student more than two years to understand the basic science--Schneider paints images in his audiences' minds with sentences that might start with "Mother Nature makes..." or end with "That's it in a nutshell."
When Schneider talks of a future when your own human cells are farmed on peptides and molded to fit into your body, he uses sentences like, "It's like a cement, but it's like a live cement. That's what people are really going for these days."
He makes his fingers walk to illustrate how a cell would become acclimated to the peptide. "The cells kind of send out little feelers," he said, wiggling his forefinger and middle finger on his desk.
And, when he explains how the cells begin to crowd each other, Schneider tightens his shoulders as if he were in a crowd.
While scientists around the world read his research, Schneider spends his off hours playing with his young son, Jack, or working on his home outside Newark with his wife, Jennifer.
Schneider says his real professional passion is to understand how molecular structure can be used to design molecular function.
After almost five years at the University, Schneider says the most gratifying experiences he's had on campus are "when students display that they've become independent scientists."
"Every professor has his or her own way of training students. For the type of work we do, it takes the students a good two-and-a-half years to learn to use the tools to do the work. At that point, I take off the training wheels and allow them to drive. After I see how they do, I may ease off or I may become more involved. The creative juices really start to flow when the students start to direct their own research, and I've been blessed with some really creative students."
Schneider's work in understanding how and why peptides self-assemble may help shed light on more complex processes involving natural proteins. Gerard J. Mangone, Francis Alison Society secretary and University Research Professor of International and Maritime Law, lauds Schneider for the possibilities inherent in his research. "Understanding the folding, misfolding and aggregation of natural proteins--processes involved in diseases like Alzheimer's, mad cow and Lou Gehrig deterioration--could be of great importance to the medical and pharmaceutical disciplines," Mangone says.