The new revolution in nano-science, engineering and technology is being driven by our ability to manipulate matter at the molecular and supramolecular level to create "designer" structures. My group uses computer simulation to discover the fundamental principles of how nanoscale systems of molecular building blocks self-assemble, and to discover how to control the assembly process to engineer new materials. By mimicking biological assembly, we are exploring ways to nano-engineer materials that are self-assembling, self-sensing, self-healing, and self-regulating. Besides producing novel functionalities, heterogeneity and patterning at the nano-scale affects materials behavior during processing and application. For example, in soft materials and complex fluids such as polymers and colloids, motion becomes highly cooperative on nanometer scales near the glass transition, resulting in dramatic changes to transport and rheology. The subtle structural features responsible for this unusual dynamics persist in the glass state, and may control physical aging, shear banding, and other complex material behavior. My group is developing theory and molecular simulation tools to understand these materials, and elucidate the nature of supercooled liquids, glasses and crystallization. In other work, we are developing strategies for dispersing colloidal particles and nanotubes in polymer melts and blends to alter the polymer's rheological and mechanical properties. To do this, we are developing hybrid multiscale simulation methods to model these complex systems from atomistic to macroscopic length and time scales within a single simulation. Our work has applications to fabrication of electronic materials, biomaterials, optical computing, nano-lithography, nano-templating, photonics, lubrication, and drug preservation.
