Hou, T.Y.Lowengrub, J.S.Shelley, M.J.2007-08-162007-08-162001-06https://hdl.handle.net/11299/3648In this paper, we present an overview of the application of boundary integral methods in two dimensions to multicomponent fluid flows and multiphase problems in materials science. We focus on the recent development and outcome of methods which accurately and efficiently include surface tension. In fluid flows, we examine the effects of surface tension on the Kelvin-Helmholtz and Rayleigh-Taylor instabilities in inviscid fluids, the generation of capillary waves on the free surface and problems in Hele-Shaw flows involving pattern formation through the Saffman-Taylor instability, pattern selection and singularity formation. In materials science, we discuss microstructure evolution in diffusional phase transformations and the effects of the competition between surface and elastic energies on the microstructure morphology. A common link between these different physical phenomena is the utility of an analysis of the appropriate equations of motion at small spatial scales to develop accurate and efficient time stepping methods.