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Topological defects in nematic liquid crystals of active colloidal rods


Active liquid crystals are out-of-equilibrium systems that display intriguing dynamic phenomena, arising from the interplay
between topological defects and collective motion. Here, we propose to experimentally study for the first time (i) the
dynamics of topological defects in the active colloidal nematic phase and (ii) the interplay between these topological defects
and collective dynamics, in three dimensions, at the single particle level, and with full control over the defects. To reach
these objectives, we first use a combination of advanced colloidal synthesis and surface modification techniques in order to
develop a model system of active colloidal rods of controlled size, aspect ratio and surface properties. We then confine this
newly developed model system in microfluidic channels, where the colloidal rods form a nematic liquid crystal. Topological
defects will be induced in the nematic phase using specific geometric constraints, which can be varied to control the
locations and strengths of the defects, or by optical trapping techniques. Finally, we use state-of-the-art confocal microscopy
and sophisticated image analysis techniques to follow, in real time and 3D real space, both the individual particle motion and
the collective dynamics in the system. Our work will thus provide experimental verification of the intriguing link between
topological defects and collective dynamics in active liquid crystals and inspire novel theories and simulation codes capable
of capturing the intrinsic complexity of coupling structure, orientation and activity.


Net EU contribution
€ 195 454,80
Wellington Square University Offices
OX1 2JD Oxford
United Kingdom
Activity type
Higher or Secondary Education Establishments
Non-EU contribution
€ 0,00
South East (England) Berkshire, Buckinghamshire and Oxfordshire Oxfordshire