title: Topological changes in bipolar nematic droplets under flow.
abstract: Bipolar liquid crystal drops moving inside microchannels exhibit periodic director field transformations due to induced circulating flows inside them. These modifications are characterized by changes in the type of point surface disclinations; they periodically change from splay to bend disclinations, implying the drop changes between bipolar and escaped concentric configurations. Upon stopping the flow, this structure does not relax to the lower energy bipolar configuration; we argue this is due to drop flattening inside the channels.
authors.affiliation: Department of Physics and HSEAS, Harvard University, Cambridge, MA 02138, USA.
authors.forename: A
authors.initials: A
authors.lastname: Fernández-Nieves
authors.forename: D R
authors.initials: DR
authors.lastname: Link
authors.forename: M
authors.initials: M
authors.lastname: Márquez
authors.forename: D A
authors.initials: DA
authors.lastname: Weitz