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Bartosz Grzybowski, Kyle Bishop, and Yuriy Chege

 

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This image shows a new technique used by researchers in Bartosz Grzybowski’s lab to recreate famous art on a very small scale.

Bartosz Grzybowski sees dynamic possibilities
on a very small scale

At first glance, Bartosz Grzybowski's research group may not appear to belong in the Department of Chemical and Biological Engineering. His postdoctoral fellows span a wide spectrum of the sciences - mathematics, physics, chemistry, and biology - and that's just what Grzybowski intended.

Grzybowski's research focuses on self-assembly, predominantly on the micro- and nanoscales. It's a cutting-edge field that provides a new level of control to recent developments in forming small structures and functional devices.

Researchers focusing on nanotechnology have been able to form a wide variety of static structures - mostly through meticulous top-down fabrication procedures under equilibrium conditions. In contrast, Grzybowski's research focuses on using nonequilibrium processes and phenomena to create systems that build themselves dynamically. This approach is inspired by biology, where components interact and organize only when powered by externally delivered energy, such as food.

"We're interested in pieces that self-organize but not just into static structures," Grzybowski explains. "We want to build things that can change and have the potential to adapt. A good example is the dynamic nanoparticle crystals we have recently synthesized. Depending on the wavelength of light that they are exposed to, the components of these unusual structures come together or fall apart. This behavior is a primitive form of adaptability at the nano­scale and is the first step towards 'intelligent' nanostructures. We are now extending this system to crystals that can be reconfigured from one form to another and thus change their optical or electrical properties."

The crystals and other structures Grzybowski's group is making can, in turn, be used as building blocks for higher-order architectures. "For example, we have used nanoscopic objects to build composite spheres and then to make microscopic crystals from those spheres," says Kyle Bishop, a chemical and biological engineering graduate student in Grzybowski's research group. "Through this bottom-up approach we were able to build materials that were 99 percent composed of metal but behaved like a flexible plastic."

Tackling the fundamental questions in this emerging area of research has presented its own challenges. "The theory and the practice behind self-organization have been limited to static structures," Grzybowski says. "There is no theory as to how and why the dynamic assemblies should form and work. Coupled with the lack of theory is a lack of experiments. Experiments are normally built on theory, but we had neither when we started."

The lack of documented knowledge explains the diverse expertise represented by the members of the research group Grzybowski recruited from all over the world. Their varied backgrounds equip the team to handle everything from creating molecules and analyzing their interactions to rationalizing the physics behind a structure's composition.

"When we first started, we had to be sure that each person understood what the other was saying," Grzybowski says. "Interdisciplinary research requires certain skills, especially in terms of communication."

"It's definitely a unique environment," says Bishop. "We feel uniquely situated to attack almost any type of problem."

The group has certainly succeeded in attracting attention. Last year alone it published more than 20 articles, and its research was featured on the cover of six leading scientific journals. In February their work on nanocrystals was published in Science . Grzybowski was recently awarded a National Science Foundation CAREER Award and the 3M Nontenured Faculty Award, and his group has secured support from a wide variety of sources, including the NSF, the National Institutes of Health, and several high-tech companies.

Despite the challenges associated with working in this type of emerging field and with such a diverse team, Grzybowski wouldn't change his approach. "Our motto is that we never do anything better, because we never do anything that anyone else has done," he says. "Life is too short to optimize someone else's work."