October 27th, 2017
Speaker: Oleg Lavrentovich from Kent State University
Using liquid crystals to command swimming bacteria
Self-propelled bacteria are marvels of nature. If we can control their dynamics, we could use it to power dynamic materials and microsystems of the future. Unfortunately, bacteria swimming is mostly random in isotropic liquids such as water and is difficult to control by factors other than transient gradients of nutrients. We propose to command the dynamics of bacteria by replacing water with a water-based liquid crystals. The long-range orientational order of the liquid crystal can be designed as uniform or be pre-patterned into various structures by a plasmonic photoalignment technique . The experiments demonstrate that the liquid crystals command the dynamics of bacteria, namely, the trajectories of swimming, polarity of motion, and distribution of bacteria in space . The study of bacteria-liquid crystal system might result in approaches to harness the energy of collective motion for micro-robotic, biomechanical, and sensing devices, as well as micro-mixing and transport of micro-cargo. The work is supported by the US National Science Foundation grants DMR-1507637 and DMS-1729509.