Home : Volume 28 : Spring 2002 :
Five COE faculty earn NSF CAREER awards

From left: Tim Shedd, Wendy Crone, Robert Carpick, Xiaochun Li and Manos Mavrikakis. (18K JPG)

Five college of Engineering faculty members are 2002 recipients of the National Science Foundation's Early Career Development (CAREER) Award. Each $375,000 award is granted on the basis of creative career-development plans that integrate research and education effectively.

Tim Shedd

Tim Shedd, assistant professor of mechanical engineering, leads the Multiphase Flow Visualization and Analysis Laboratory. He studies fundamental behaviors of multiphase flow, with specific attention to fluid systems common in refrigeration and air-conditioning applications.

His team develops experimental techniques for quantifying complex interactions between flowing vapors, liquids and solids. They visualize and measure liquid film development throughout a condensation process and study the inception of waves that are critical to heat transfer. In collaboration with faculty in the mechanical engineering department as well as partners in the high-end computing industry, Shedd plans to expand these applications to novel two-phase electronics cooling projects. He also sees opportunities for collaborative research in the power generation industries.

Shedd will enhance education in the thermal sciences through live demonstrations of fluid flows in the lab, through in-class, real-world, project-based collaborative learning techniques, and by involving several undergraduate research assistants. Two portable flow demonstration units are planned: one for demonstrating two-phase flow and visualization techniques and the other for simultaneously visualizing single-phase flow behaviors and measuring heat transfer.

Robert Carpick

As nanomaterials increase in use, the need to understand their tribology — friction, adhesion, lubrication and wear properties — also becomes more urgent. At small scales, surface effects start to dominate over bulk effects, so surface forces such as friction and adhesion play a critical role. Robert Carpick, assistant professor of engineering physics, is studying the fundamental relationship between frictional energy dissipation and atomic vibrations.

Using an atomic-force microscope, Carpick will measure friction at the atomic scale as a function of the sliding materials' vibrational properties, and he will manipulate these vibrational properties by changing the materials' isotopic composition — for example, by using heavier atoms. With this research, he hopes to provide a quantitative experimental basis that will enhance the understanding of the relationship between frictional energy dissipation and vibrational properties. Further, he hopes this knowledge will enable researchers to design nanostructured materials and devices with optimized tribological and other properties via isotopic engineering.

With Assistant Professor Wendy Crone, Carpick will co-develop an advanced seminar course in nanotechnology to be used both locally and as a general model. He will also develop outreach materials directed toward the public, kindergarten through 12th-grade students, and traditionally underrepresented groups in engineering.

Wendy Crone

Wendy Crone, assistant professor of engineering physics, is studying shape-memory alloys. The unique materials, which have applications in the biomedical, aerospace, microelectronics and automotive industries, have a crystallographic structure that enables them to undergo large deformations and then return to their original shape. However, researchers must develop reliable shape-memory alloy materials and devices, and Crone will investigate the effect of process-induced microstructure on the materials' fracture and fatigue behavior.

In addition, she will study how grain refinement affects fracture behavior for a variety of grain sizes, and develop experimental models that explain mechanisms that influence fracture and fatigue in nickel-titanium and copper-based shape-memory alloys.

Through the education component of the grant, Crone will develop new course material in the areas of nanomaterials, micromechanics and fracture mechanics to educate both undergraduate and graduate students about ways in which mechanics contributes to new technologies. This expanded course material also will have an international impact via the Smart Materials Exemplar of the Worldwide Universities Network, an international network of researchers and educators.

Xiaochun Li

Xiaochun Li, assistant professor of mechanical engineering, is seeking ways to integrate two fields — layered manufacturing and smart materials and structures. According to Li, little work has been done in integrating the two fields at the mesoscale (from 100 microns to 10 millimeters). "This is an emerging field," he says.

According to Li, the mesoscale layered manufacturing technologies have significant implications for the design and fabrication of mesoscale complex structures, filling the voids of 2-D microscale processes (silicon surface micromachining and LIGA process) and 3-D macroscale miniature machining. His research provides a solid platform for a seamless integration from CAD to the realization of complex 3-D mesoscale smart parts in a wide selection of materials.

In addition, Li plans to conduct research on fundamental issues related to mesoscale layered manufacturing processes. He plans to integrate laser-assisted shape deposition manufacturing and laser direct write to build mesoscale smart structures containing embedded microsensors and actuators. Li's goal is to provide insights into how industry can rapidly manufacture smart devices that perform faster and with better precision. The educational plan of this award is to improve the existing curriculum in manufacturing by developing new interdisciplinary elements that integrate the fields of layered manufacturing (rapid prototyping), micro-/nano-manufacturing, and smart materials and structures.

Manos Mavrikakis

Manos Mavrikakis, assistant professor of chemical engineering, is searching for more suitable catalysts for fuel-cell electrodes. Government and industry are shifting focus from gasoline engines to fuel-cell technology to efficiently power cars and reduce the nation's reliance on foreign oil. Direct methanol fuel cells (DMFC) hold the promise of direct conversion of methanol to electricity, a process that can be as much as four times more efficient than combustion in internal combustion engines.

However, before DMFCs can be made commercially viable, a number of technological problems must be solved. Chief among these is the need to develop an electrooxidation catalyst that will both produce a high power density and be resistant to carbon monoxide (CO) poisoning over time. Poisoning occurs as the CO produced from methanol oxidation sticks irreversibly to the catalyst surface, prohibiting further catalytic activity of the electrode.

Using state-of-the-art theoretical tools and massively parallel supercomputers, Mavrikakis seeks fundamental understanding of methanol behavior on existing catalysts and new alloys that may lead to improved catalyst performance. His work is aimed at both oxygen reduction at the cathode and methanol oxidation at the anode, taking into account both electric field effects and solvent effects.

His research team is looking at CO adsorption on various alloys to determine which give the lowest binding energy, and thus have the greatest potential for CO tolerance. On the cathode side he is looking at cathode catalytic bond breaking of the oxygen-oxygen bond. Subsequent investigations of various alloys will include the total cathode reaction, which typically involves water formation. The results of these studies could produce faster cathode reactions.

As part of the educational component of his award, Mavrikakis is planning to develop computational chemistry modules which will bring the excitement of atomic-level thinking to undergraduate thermodynamics and kinetics courses. The knowledge is important to engineering undergraduates, who will become active participants in the nanoscience and nanoengineering revolution.

Content by perspective@engr.wisc.edu

Date last modified: Tuesday, 07-May-2002 11:29:00 CDT
Date created: 07-May-2002

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