Soft-Matter & Biophysics
Soft Condensed Matter
Given its scope and applications, soft condensed matter lies at the very intersection of physics, chemistry, and biology. Soft condensed matter physics, a subfield of condensed matter physics, focuses on the study of both static and dynamic properties of matter and materials at energy scales where thermal fluctuation dominates. As such, quantum aspects are negligible. Typical “soft” systems of interest include liquids, colloids, polymers, foams, gels, granular materials, and glasses, as well as a variety of biological and complex materials. They derive their many interesting properties from a competition between electrostatic interactions, van der Waalsforces, and entropic effects. This fast-growing research field is interesting not only for its use of classical geometry and deep theoretical concepts associated with symmetry breaking, phase transitions, or emergent phenomena, but also for its immense potential for applications in technology (from ceramic paints and adhesives to liquid-crystal displays) and biological materials (blood, muscle, skin, tissue, gels, membranes, milk, and vesicles are all examples of “soft” materials).
Biological molecules often have complex structures that are dictated by the functions they must perform. Despite this complexity, the molecules are self-organized, typically built from simple building blocks such as amino acids, nucleic acids, lipids and sugars, and often function in a crowded intracellular environment that uses complicated signaling pathways to initiate crucial biological functions. Understanding the molecules, their assembly, and their interactions is of paramount importance to molecular biology and biological physics. There is also much interest in new materials that can be derived by combining biological molecules in unusual ways, or by combining biological molecules with synthetic species, including nano particles and inorganic interfaces. Northwestern and Argonne National Lab’s Advanced Photon Source have a number of unique structural tools available for the characterization of biomolecules. In-house methods include high-resolution TEM coupled with surface analytical techniques, an array of electron and scanning probe tools, and laser spectroscopy techniques. State-of-the-art computer simulations employing molecular dynamics and Monte Carlo methods are facilitated by Northwestern’s Quest high-performance computing facility.