Shape-Shifting Materials are Goal of New Nanotechnology Project

BUFFALO, N.Y. -- An international research team has received a $2.9 million grant from the Air Force Office of Scientific Research to design nanomaterials whose internal structure changes shape in response to stimuli such as heat or light.

Each of these novel materials will be constructed from three types of components: inorganic nanoparticles with desired optical or electrical properties; peptides that bond to these nanoparticles; and special molecules called spacers, which sit between the peptides and bend in the presence of heat, light or other triggers.

When stimulated, the spacers will cause the arrangement of nanoparticles within the material to morph -- a process that can lead to interesting and useful effects.

Shape-shifting materials of the kind the researchers are planning to create could have use in applications including color-changing sensors and plasmonic circuits that divert light in two directions.

The project is being led by Paras Prasad, SUNY Distinguished Professor in the University at Buffalo's departments of chemistry, physics, electrical engineering and medicine, and executive director of UB's Institute for Lasers, Photonics and Biophotonics (ILPB). Funding comes from the Mathematics, Information and Life Sciences Directorate of the Air Force Office of Scientific Research, with Hugh DeLong in that office serving as program manager.

Prasad's fellow investigators include Aidong Zhang, professor and chair of the Department of Computer Science and Engineering at UB; Mark T. Swihart, professor of chemical and biological engineering at UB and director of the UB 2020 Integrated Nanostructured Systems Strategic Strength; Tiffany R. Walsh, associate professor at the Institute for Frontier Materials at Deakin University in Australia; and Marc R. Knecht, associate professor of chemistry at the University of Miami.

The palette of parts the team will use to build the nanomaterials includes spacers of different sizes, along with seven types of nanoparticles -- gold, silver, silica, iron-oxide, iron-platinum, cadmium-sulfide and zinc-sulfide.

To identify the combinations of components that will produce the most interesting materials, the scientists will use high-throughput experiments and data-mining techniques to screen and analyze the vast number of possible combinations of nanostructures, biomolecular linking elements (the peptides) and assembly conditions.

"One of our goals is to contribute to the fundamental understanding of how the spatial arrangement of nanoscale components in materials affects their optical, magnetic and plasmonic properties," Prasad said. "The high-throughput techniques we are using were pioneered in the field of bioinformatics, but also have extraordinary promise in the exploration of advanced materials."

Zhang said, "The computational capabilities offered by informatics and data mining will enable us to maximize the value of our data regarding the nanoassemblies, to generate and to construct new assemblies that span a wide range of inorganic and bimolecular components so as to achieve desired combinatorics-based properties."

To process the enormous amounts of information the study will generate, the scientists will rely on the computational capabilities of UB's supercomputing center, the Center for Computational Research (CCR).

The project demonstrates UB's increased success in attracting large multidisciplinary research grants, Swihart said. In recent years, the university has encouraged interdisciplinary collaboration under the umbrella of eight broad areas known as the UB 2020 Strategic Strengths. The new research engages faculty in two of these strengths: Information and Computing Technology, and Integrated Nanostructured Systems, which Swihart leads.

"This project is an example of the enormous research opportunities at the intersection of materials science and informatics," said Alexander N. Cartwright, UB vice president for research and economic development. "UB is poised to dramatically grow research efforts in this area through the university's recently designated New York State Center of Excellence in Materials Informatics.

"The scientists leading this project are experts in several different fields, and they are bringing their skills and expertise together to conduct materials research," Cartwright said. "This kind of collaboration is at the heart of what UB's new Center of Excellence strives to achieve -- by drawing on the talents of researchers across disciplines, we can pursue advanced and complex research projects."