Self-organization of soft matter mediated by mechanical stress. Role of mechanical stress in information transfer in a cell
Ph.D., San Diego, 1971.
My research concerns collective mechanisms for creating spontaneous structure in forms of conventional condensed matter such as polymer liquids, evaporating liquid drops, layer-forming surfactant micelles and thin elastic sheets. All these materials when subjected to structureless external forces develop new forms of spontaneous structure at a fine length scale, such as the sharp folds of a crumpled sheet or the thin ring stain left when a drop of dirty fluid has evaporated. These new forms of force-induced structure often arise from fundamental mechanical properties such as the competition between bending and stretching energy in an elastic sheet or between evaporative flows and capillary forces in an evaporating drop. They may arise from fundamental statistical properties such as the randomness of a chain polymer molecule or the random, tenuous structure of a colloidal aggregate. In either case the fundamental origins of the resulting structures mean that they can be used and manipulated in a wide range of material realizations independent of the specific properties of the materials.
Robust fadeout profile of an evaporation stain T. A. Witten, EPL 86 64002 (2009)
Chiral sedimentation of extended objects in viscous media Nathan W. Krapf, Thomas A. Witten, and Nathan C. Keim, Physical Review E 79 056307 (2009)
Stress focusing in elastic sheets T. A. Witten, Reviews of Modern of Physics,79
Structured fluids: polymers, colloids, surfactants (Oxford University Press: 2003)
Geometric origin of excess low-frequency vibrational modes in amorphous solids Matthieu Wyart, Sidney R. Nagel, T.A. Witten Europhysics Letters 71 1-7(2005)