Late at night, as a release from the stress and demands of a successful academic career, Tomasz “Tomek” Kowalewski sometimes spends an hour or two practicing the piano.
A beautiful piece of music is a perfect blend of order and chaos, he says, where the listener can follow the composition, yet still be surprised by its arrangement. The same delicate balance holds true when it comes to macromolecules:
“These materials have a lot of unpredictability and wildness that can lead to interesting things, but on the other hand, they are crafted precisely with well-defined structures,” Kowalewski says.
Kowalewski, associate professor of chemistry, is working to bring order out of the chaos of carbon-based macromolecules at the nanoscale. His efforts to understand and harness the unusual properties of carbon at this level could help to create a revolutionary new generation of materials for use in solar panels, consumer electronics, switching devices, smart tags and lighting displays.
“The scientific challenge is to take carbon, which is usually equated with insulating materials, and fashion it into a structure that allows it to conduct electricity,” he says.
Kowalewski didn’t set out to study macromolecules — or chemistry, for that matter. Kowalewski grew up in the gritty industrial town of Lodz in central Poland. His father managed a textile factory, and his mother was a dentist who instilled in him a respect for physics and mathematics.
“She brought me up with the expectation that these are really the fundamental tools we need to analyze and make sense out of the world,” he says.
Kowalewski majored in solid-state physics as an undergraduate at Lodz Polytechnic Institute and went on to earn his doctorate in polymer physics from the Polish Academy of Sciences. He left Communist Poland at the height of the Cold War and accepted a position as a research professor at Washington University in St. Louis with chemist Jacob Schaffer, a 1960 Carnegie Tech graduate. In Schaffer’s lab, Kowalewski became an authority in the physics underlying atomic force microscopy (AFM), a very high-resolution tool for imaging, measuring and manipulating matter at the nanoscale. Unlike the electron microscope, AFM can be used to look at biological macromolecules while they are at work in their native environment.
In the mid-1990s, Kowalewski began to use AFM to examine the insoluble plaques made from the protein fragment beta amyloid, which have been implicated in Alzheimer’s disease. He demonstrated for the first time how these peptides self-aggregate and interact with the surfaces of the brain. In addition, he garnered much attention for his AFM studies on protein binding during DNA repair and genetic recombination. Kowalewski came to Carnegie Mellon in 2000, where he continued his research in AFM physics and Alzheimer’s disease along with then graduate student Justin Legleiter (S’05).
“Tomek is very thorough so he sets a great example,” says Legleiter, now a postdoctoral fellow at the Gladstone Institute of Neurological Disease in San Francisco. “He really places emphasis on the quality of your work and making sure you do things correctly.”
Though still fascinated by biological systems, Kowalewski was drawn to Carnegie Mellon by the group of scientists working in polymer synthesis such as fellow Polish Academy graduate Krzysztof Matyjaszewski, J.C. Warner Professor of NaturalSciences, and the University’s Vice President of Research and professor of chemistry, Richard McCullough.
“We want synthetic molecules to do something similar to what happens in nature,” Kowalewski says. “But nature never tried it the way we are.”
Specifically, Kowalewski and his colleagues are seeking to harness the electronic properties of self-assembling nanocarbon arrays made from block copolymers, or long-chain molecules with distinct “blocks” of chemically different repeating units. They found that block copolymers made from polyacrylonitrile and polyacrylic acid spontaneously self-assemble into well-ordered nanostructures such as cylinders, balls or sheets. Kowalewski then adapted a method called zone casting to transform these chemical precursors into carbon arrays without destroying their nanoarchitecture.
The intricate nanostructures give the carbon arrays conducting power so they could be used to make electronic devices. And since they organize on their own, unlike highly engineered silicon chips, manufacturers wouldn’t require multi-million dollar, energy-hungry fabrication plants to produce them.
“If you choose the right kinds of molecules, they will do it themselves in a vat,” Kowalewski says. “That’s the pipedream, anyway.”
Photovoltaic technology that converts sunlight into electrical energy is one especially promising application for carbon nanostructures, according to Kowalewski. Cheaper, low-tech solar panels made from these novel organic materials could help to end our dependence on nonrenewable energy sources, he says.
As principal investigator of a Nanoscale Interdisciplinary Research Team funded by the National Science Foundation, Kowalewski conducted this research as part of a four-year project to develop a new generation of nanostructured carbon molecules with electronic properties. His vision and leadership have proven invaluable, says Matyjaszewski, professor of chemistry.
“Chemistry is sometimes focused on making materials without any applications in mind,” says Matyjaszewski. “We need to build a bridge somehow between what is made and how it is processed and what it can be good for. Tomek is a very creative person with the unusual breadth and deep understanding of chemistry needed to make these connections.”
How quickly carbon nanostructures make their way into electrical components is a function of the resources that are dedicated to this innovative polymer chemistry, says Kowalewski, who is working on how to achieve better control over the structure of these materials. He remains optimistic that this bottom-up approach to manufacturing that draws its inspiration from biology will have a growing impact on research and industry.
“Carbon won’t replace silicon-based electronics, but it will put electronics in places it wouldn’t be otherwise,” Kowalewski says. “And that makes it hard to resist.”