November 9, 2006
Researchers to present advances in energy, health, technology at chemical engineering conference
By David Orenstein
At the annual meeting of the American Institute of Chemical Engineers (AIChE) in San Francisco Nov. 13-17, Stanford University researchers will report advances in areas such as health, clean energy, electronics and nanotechnology.
"The papers being presented come from many different departments in several schools and institutions at Stanford, reflecting that research that crosses traditional boundaries within universities is essential to tackling today's most challenging problems," says Jim Plummer, dean of the School of Engineering.
Founded in 1908, AIChE is a professional association of more than 40,000 chemical engineers in 92 countries. Its members work in corporations, universities and government using their knowledge of chemical processes to develop products. The AIChE meeting is the largest annual gathering devoted to chemical and biomolecular engineering and advances in nanotechnology. The meeting will be held at the Hilton San Francisco, 333 O'Farrell Street. For details, visit http://www.aiche.org.
Health and the environment
One meeting highlight concerns research into the molecular details that may underlie Alzheimer's disease. On Monday, Nov. 13, at 12:45 p.m., graduate student John Kirkwood, from the research group of chemical engineering Professor Gerald Fuller, will discuss experiments describing how chains of amino acids called amyloid beta-peptides interact with lipids and water. In brain tissue, such interactions may explain how amyloid beta-peptides accumulate on neural cell membranes and disrupt their workings, causing cellular malfunction and incurable dementia.
Several other presentations by Stanford scholars will focus on making alternative energy technologies more technically and economically viable. For example, a major question that must be answered before fuel cell vehicles can be powered by hydrogenas part of the so-called "hydrogen economy"is how vehicles will store that hydrogen. Hydrogen compressed in tanks could explode. Metal hydrides, or solid chemical formulations, are either too heavy, too slow to charge or require too much heat to relinquish the stored hydrogen for use by the fuel cell. A group led by materials science and engineering Professor Bruce Clemens and chemistry Professor Hongjie Dai is pursuing another method that might be more safe and effective: storing hydrogen in carbon nanotubes. On Wednesday, Nov. 15, at 3:15 p.m., graduate student Yong-Won Lee will describe research showing that carbon nanotubes can store more than four times more hydrogen when peppered with the metal palladium than they can without such alteration, pointing the way toward increasing their hydrogen capacity to practical levels.
Two other fuel cell highlights, both coming out of the research group of mechanical engineering Associate Professor Juan Santiago, deal with overcoming technical hurdles that have made the power devices too inefficient, unreliable and expensive compared to conventional vehicle fuel systems or electric batteries. A significant part of the reason fuel cells are not more competitive is because they require moving small quantities of liquid fuel, water and air through labyrinths of tiny channels either to or from reaction sites. One solution, Santiago says, could be to incorporate small "electroosmotic" pumps that use electric fields rather than moving parts to push liquids around. On Wednesday at 9:35 a.m., graduate student Shawn Litster will discuss the use of such pumps to redistribute water supplies around the cell such that no area dries out or floods. Later that day at 3:40 p.m., fellow graduate student Cullen Buie will present research on using similar pumps to deliver significant amounts of hydrogen-rich methanol fuel with high reliability and very low power.
Electronics and nanotechnology
In the realm of information technology, Charles Musgrave, an assistant professor of chemical engineering, will present his group's research on integrating amino acids into nanoscale electronic devices. The talk will take place Tuesday, Nov. 14, at 10:30 a.m. The research explores the manufacture of both hybrid bio-inorganic circuits and biologically sensitive sensors using amino acids as nanoscale building blocks and the nanofabrication infrastructure of modern chip-making technology. Many researchers, including several at Stanford, are looking at a variety of organic molecules for possible use in circuits, but Musgrave is investigating amino acids, the building blocks of proteins, because they appear to be particularly versatile in giving engineers options for tuning these devices for different applications.
Meanwhile, electrical engineering Assistant Professor Peter Peumans will present his group's approach to improving the energy efficiency of organic light-emitting diodes (OLEDs), a carbon-based technology that has begun to appear in futuristic displays on mobile phones and other electronics. As pretty as OLEDs look, their structure internally reflects up to 80 percent of the light they emit, meaning it does not reach the eye. To make them bright enough requires a large current, which drains battery power in portable devices. While researchers have tried to solve this problem, their results have caused blurring of the display or other problems. On Thursday, Nov. 16, at 3:45 p.m., Peumans will discuss success in adding a special mirror structure that controls the emission of light and therefore wastes less energy.
Capping off the conference will be a daylong symposium, Friday, Nov. 17, honoring Robert J. Madix, a Stanford professor emeritus of chemical engineering. The talks, including one by Madix at 5:20 p.m., will cover the chemical reactivity of molecules on solid surfaces. Madix will describe how studies on single metallic crystals have yielded a vast understanding of the movement and interaction of chemicals during a variety of reactions.
"Professor Madix's work has paved the way for the discovery of high-performance catalysts and has opened new vistas as to how one thinks about chemical reactivity in general," said Channing Robertson, a chemical engineering professor and senior associate dean for faculty affairs in the School of Engineering. "He has educated and trained a new generation of pioneers in this important area. His impact has been and will continue to be substantial in such applications as fuel cells, chemical synthesis and novel materials."
David Orenstein is the Communications and Public Relations Manager at the Stanford School of Engineering.
The AIChE annual meeting will be held Nov. 13-17 at the Hilton San Francisco, 333 O'Farrell Street. For details, visit http://www.aiche.org. A photo of Professor Gerry Fuller is available on the Web at