Condensed Matter Seminar

Wed, 09/19/2012 - 16:00 - 17:00
Zvonimir Dogic, Brandeis University

Zvonimir Dogic, Brandeis University

"Hierarchical active matter: from beating bundles to active gels, streaming liquid crystals and motile emulsions"

Laws of equilibrium statistical mechanics impose severe constraints on the properties of conventional materials. For example, equilibrium materials assembled from inanimate components cannot perform work and thus never exhibit autonomous motility. To overcome these restrictions, attention has focused on studying far-from-equilibrium materials assembled from animate microscopic objects. The emerging field of active matter promises an entirely new category of materials, with highly sought after properties such as autonomous motility and internally generated flows. In this vein, I will describe recent experiments that have focused on reconstituting dynamical structures from purified biochemical components. In particular I will describe recent advances that include: (1) assembly of a minimal model of synthetic cilia capable of generating periodic beating patterns, and conditions under which they exhibit metachronal traveling waves, (2) study of 2D active nematic liquid crystals whose streaming flows are determined by internal fractures and self-healing as well as spontaneous unbinding and recombination of oppositely charged disclination defects, (3) reconstitution of active gels characterized by highly tunable and controllable spontaneous internal flows, and (4) assembly of active emulsions in which aqueous droplets spontaneously crawl when in contact with a hard wall.