Stephen Garoff-Dept of Physics - Carnegie Mellon University

Stephen Garoff

Professor and Department Head, Physics

Office: Wean Hall 7325
Phone: 412-268-6877
Fax: 412-681-0648


Ph.D., Harvard University


The properties of interfacial regions where fluid or solid phases meet dominate the behavior of many natural and technical processes.  Wetting, friction and adhesion, corrosion, stability of emulsions (droplets of liquids in another liquid) or colloidal suspensions (solid particles suspended in a liquid) are some examples. But attaining a fundamental understanding of their behavior challenges our experimental abilities because these interfacial regions are structurally complex on a molecular scale, are seldom homogeneous on a microscopic scale, and may not even be in equilibrium. Often monomolecular layers along the interfaces dominate the behavior of the interface and the macroscopic phenomenon. In the Interfacial Physics Group we attempt to build an understanding of interfacial phenomena on the molecular, microscopic, and macroscopic levels. In our research, we probe many different liquid systems, including aqueous and non-aqueous fluids and solutions, surfactants and polymers, and even metals interacting with a variety of solids, including glasses, oxides and metals. We employ a range of techniques including x-ray, neutron, and optical techniques, atomic force microscopy, rheology, as well as UHV and non-UHV materials preparation. Presently, we focus on wetting, friction, and colloidal forces.  Our program draws on a broad range of scientific phenomena such as random field effects, nonequilibrium states, hydrodynamics, and noise in hysteretic systems. The results of our research reveal the scientific underpinnings of such technologies as coatings, adhesion, colloidal stability, and multiphase fluid flow.

We maintain extensive collaborations with groups in the Material Science, Chemical Engineering an Biomedical Engineering Departments at Carnegie Mellon as well as in the University of Pittsburgh Medical School.  We participate in the programs of the Center for Complex Fluids Engineering. We also work on applications of our research through projects funded by industry. For more details on our group, see Interfacial Physics Group.

Selected Publications