title: Optothermally driven colloidal transport in a confined nematic liquid crystal.
abstract: We demonstrate transport of microparticles by rapid movement of a laser spot in a thin layer of a nematic liquid crystal. The transport is achieved by fluid flow, caused by two different mechanisms. The thermoviscous expansion effect induces colloidal transport in the direction opposite to the laser movement, whereas thermally induced local melting of the liquid crystal pulls the particles in the direction of the laser movement. We demonstrate control of colloidal transport by changing the speed of the laser trap movement and the laser power. We anticipate that complex optofluidic colloidal transport could be realized in the nematic liquid crystal using a channel-free optofluidic approach.
authors.affiliation: J. Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia. miha.skarabot@ijs.si.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-5734-7839
authors.initials: M
authors.lastname: Škarabot
authors.affiliation: J. Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia. miha.skarabot@ijs.si and Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000, Ljubljana, Slovenia.
authors.forename: N
authors.initials: N
authors.lastname: Osterman
authors.affiliation: J. Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia. miha.skarabot@ijs.si and Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000, Ljubljana, Slovenia.
authors.forename: I
authors.initials: I
authors.lastname: Muševič