Wed October 24th 2018
16:00 – 17:00
Seminar Nematic Active Double Emulsions
Babak Vajdi Hokmabad


The capability to produce controllable, active microcapsules would present a leap forward in the development of artificial cells, microreactors, and microsensors. For inactive microcapsules, double emulsions are already widely used as a platform for synthetic biology and microchemistry. However, a significant challenge remains in combining activity, stability, and control. Building on the established system of active emulsions here we present a new approach to the problem of encapsulation by using nematic active double emulsions, where a solubilization mechanism induces motility and the nematic structure provides stability.
In contrast to the well-established case of emulsions at rest where the interplay of interfacial forces and slow hydrodynamics leads to slow thin film drainage and coalescence, in a non-equilibrium system the strong hydrodynamics can overcome the interfacial forces and accelerate the coalescence. We show that using a nematic liquid crystal as the shell material will impose a nematoelastic force on the internal droplet and act as a topological barrier against the coalescence of the core droplet with the outer phase. I will further discuss the peculiar Marangoni flow induced self-propulsion mechanism where the interplay of spontaneous symmetry breaking and autochemotaxis results in a novel “shark-fin meandering” motion of the shell in a 2D-confined geometry and a helical swimming in 3D. This behavior can be controlled or switched off via chemical gradient and topographical guidance or through shell topology variation.
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The 10th Complex Motion in Fluids 2021
Max Planck Gesellschaft
Centre for Scientific Computing