Pursuing the Infinite Promise of the Infinitesimally Small
Imagine the economic and environmental benefits of new nanomaterials that could generate energy from waste heat typically lost by cars, electronics, power plants and factories. And consider how the economy could be transformed via yet-to-be-invented nanoscale materials with optimized electrical, magnetic, optical or thermal properties.
Tantalizing goals like these remain elusive. While scientists could conduct millions of possible nanoscale experiments, what they lack, in layman's terms, are guidelines for recipes, ingredients and preparations that would yield optimal results. That's where Penn Engineering's Jennifer R. Lukes is making her mark as a leader in atomistic computer modeling, which validates and advances the emerging principles of nanoscale science with vast quantities of data. While she specializes in thermal transport research, Lukes' computer simulations identify potentially fruitful experiments for scientists and engineers looking to exploit many different useful properties that emerge in materials 100 nanometers or smaller—literally at the scale of individual atoms.
"We can model thousands of variations in experimental design and materials, like a combinatorial problem, to identify good candidate structures that are likely to obtain a desired thermal, electrical, magnetic or material strength capability," says Lukes, associate professor and graduate group chair in the department of Mechanical Engineering and Applied Mechanics."Pinpointing promising combinations of particle sizes, structures and arrangements of atoms worth developing in the lab offers experimentalists huge time and cost savings."
As she wrangles complex data from computer 'experiments' on arcane-sounding materials such as carbon nanotubes, superlattices, nanowires, and ultra thin films, Lukes envisions how insights obtained about the unique properties of nanomaterials might make a difference in the world. Working with collaborators, she is exploring ways to develop metamaterials with specific electrical, magnetic, optical and thermal properties. And Lukes is investigating ways to address the severe thermal issues in advanced electronics, radar, and other systems by probing, at the atomic scale, the cooling performance of tiny carbon nanotube heat sinks and boiling fluorocarbon liquids.
"At the nanoscale, the physical properties of materials are no longer what they are in the textbook," says Lukes, whose approach to modeling the unique thermal properties that emerge at the nanoscale may well appear in chapters of future textbooks.
Lukes is mindful of her responsibility to the next generation of engineers. Today, she says, "I make a point of talking to the very talented undergraduates to encourage the pursuit of an engineering Ph.D." An enthusiastic participant in initiatives to strengthen interest in science and engineering among minorities, she says, "Just to plant the seed in young people's minds that people who look like me are doing this kind of work is fantastic."
View the full article in Penn Engineering magazine "Pursuing the Infinite Promise of the Infinitesimally Small" by Jessica Stein Diamond.