Dancing from turbulence to active machines: Transitions between orderly and disorderly flowing active nematics

21 Feb
Applied Mechanics Colloquia
Tyler Shendruck (Rockefeller University)
Wednesday, February 21, 2018 -
4:00pm to 5:00pm
Pierce 209

While traditional fluids only flow when acted upon, a remarkable class of materials can spontaneously flow by means of their own internal energy. These “active fluids” comprise a wide range of biological and synthetic materials that are driven out of equilibrium by energy injection from their microscopic elements, such as swimming bacteria or motor protein-microtubule bundles. The typically elongated nature of these constituents frequently favors nematic alignment; however, their activity disturbs orientational order, continuously creating and annihilating pairs of topological defects. While these defects play a pivotal role in generating the spontaneous disorderly flows of mesoscale turbulence, they also have potential for novel applications if spatiotemporally ordered flow states can be produced. This talk will describe the transitions between complex ordered flows produced by configurations of “dancing” defects and disorderly active turbulence within microchannels. The knowledge gained from studying such “living” flows within confining geometries is essential for future designs of hybrid bio-mechanical microfluidic devices that have the potential to work in conjunction with active biological fluids, rather than against them.