Thursday, July 14th 2022 at 16:00 PM
Postdoctoral Research Scholar, Pritzker School of Molecular Engineering, University of Chicago
Light-activated 2D micro-swimmers in a thermotropic liquid crystal Antonio Tavera-Vazquez Abstract Inspired by the motility of micro-biological structures, the design of self-propelled systems has become crucial to the material sciences for engineering novel technologies. Studies on external fields-activated colloids have been done largely within simple liquids, however, we have gone one step forward by using a structured material that displays liquid crystalline mesophases as the host medium. In this seminar, I will show a quasi-2D active system consisting of solid micron-sized platelets that self-propel in the presence of light, immersed in a thermotropic nematic liquid crystal (LC). Since the local temperature of the medium is tunable while shining light on the platelet, it locally induces the nematic-isotropic phase transition of the LC, as the absorbed energy is released as heat. The irregular morphology of the platelet contributes to the local symmetry-breaking in the system. As a result, a net force is induced on the platelet, and hence the platelet moves. An introduction to molecular dynamics and continuum simulations is also given to figure out the physical phenomena occurring in the system.
Biography
Antonio was born in Morelia, Mexico. He obtained his BS degree in physics and mathematics from the University of Michoacán. After that, he moved to Mexico City and got his MS degree in physics in 2014 at the Institute of Physics from the National University of Mexico. In the same place, he obtained his Ph.D. degree in physics in 2019, focused on the experimental study of mechanical and dynamical responses of thread-like morphologies in complex fluids by rheology, microrheology with dynamic light multi-scattering, and static scattering techniques. Right after, he joined Professor Juan de Pablo’s group at the University of Chicago, where he currently conducts experimental research in liquid crystals, with focused attention on activating microparticles triggered by light within thermotropic liquid crystals. Antonio has also participated in different educational and outreach programs, as training students for the Physics Olympiads, science fairs, and more recently in “Clubes de Ciencia” in a collaborative effort between Mexican and US institution.