Mathematical Soft Matter Unit (Eliot Fried)
Unit Head: Professor Eliot Fried
The relatively new but rapidly expanding field of soft matter focuses on materials whose basic structural elements consist of many atomic or molecular subelements. These materials may be liquid, solid, or somewhere in between the two, and can generally be easily deformed by force, thermal, magnetic, electric, and other external fields. Due to their unique physics, they play a large and ever-growing role in applications. Familiar examples of soft matter range from foods (yogurt) and personal care products (shampoo) to cushioning materials (memory foam), coatings (paint), and construction materials (asphalt). Other important but somewhat less well known uses of soft matter include liquid crystals in display devices, colloidal dispersions for materials synthesis, lipid vesicles for drug delivery, hydrogel scaffolds for tissue engineering, and fracturing fluids in oil extraction.
The characteristic lengths of the basic building blocks of soft matter range from tens of nanometers to micrometers. Since the interactions between these elements are significantly weaker than those between the atoms of a crystal, for instance, even relatively small external stimuli may induce structural ordering of the elements and lead to pronounced shape changes. Soft matter systems may also self-assemble spontaneously and exhibit different phases. For these and other reasons, soft matter provides a fertile setting for scientific discovery and technological innovation. The field has attracted attention from physicists, chemists, biologists, engineers of all kinds, and applied mathematicians. It is inherently interdisciplinary!
To adequately take advantage of the promise of such materials, a sound theoretical understanding of them is required. Research in the Mathematical Soft Matter Unit focuses on theoretical and applied problems in soft matter, using a combination of techniques from statistical and continuum mechanics, differential geometry, asymptotic analysis, bifurcation theory, and large-scale scientific computing. Additionally, a laboratory for performing experiments designed to test and inspire theoretical predictions opened in July 2015 and is now fully operational. Systems of recent interest include high-density lipoproteins, perforated lipid bilayers, suspensions of self-propelled agents like bacteria, and sessile drops undergoing evaporation and condensation.
Acetone droplet in a Leidenfrost state on 75°C water
The movie presents an acetone droplet in a Leidenfrost state on 75°C water surrounded with an aerosol made from water. The movie is 83 times slowed down. The droplet has a diameter of about 2.9 mm. A thermocapillary Marangoni flow is present in the droplet and due to the evaporation of acetone on the water surface, a solutocapillary Marangoni flow is present on the surface of the water.