Principal Investigator Mehran Kardar
Project Website http://www.nsf.gov/awardsearch/showAward?AWD_ID=1206323
Project Start Date September 2012
Project End Date August 2017
This award supports theoretical and computational research, as well as educational activities, towards understanding the influence of boundaries on fluctuating fields. Fluctuations, whether the result of the random thermal motion or a consequence of Heisenberg's famous uncertainty principle are ubiquitous in nature, and particularly pronounced in small systems. While fluctuations imply uncertainty, they can be utilized to manipulate forces and to achieve preferred outcomes. Specific examples include: (1) Far from empty, the vacuum pulsates with electromagnetic fluctuations of quantum and thermal origin. Objects in vacuum modify these fluctuations and in turn experience forces, the much studied Casimir and van der Waals forces. The motion of the immersed objects far from the steady state of equilibrium are less well studied and include phenomena such as friction of vacuum, emission of radiation, and violations of classical blackbody radiation results at short scales. The latter can for example be utilized to increase heat transfer across a short gap by orders of magnitude. (2) Thermal fluctuations in soft matter, for example near critical fluid mixtures, result in forces of controllable range that can be used to assemble colloids into desired patterns. How are these forces modified by the shape and structure of the boundary, for example by etching specific chemical or geometrical patterns? (3) Biological systems form patterns at different scales, from sub-cellular to organism, despite, or because of, non-equilibrium fluctuations. The influence of boundary shapes will be explored for aggregation processes that involve diffusion. Education and development of human resources are an important aspect of this project. The research is interdisciplinary, aimed at applying methods from statistical physics to a wide range of scientific problems. The research is closely linked to courses taught by the PI, which through textbooks and dissemination by the web have an impact on a broader scientific community.