Related papers: Microswimmers knead nematics into cholesterics
We use numerical simulations to probe the dynamics of concentrated suspensions of spherical microswimmers interacting hydrodynamically. Previous work in the dilute limit predicted orientational instabilities of aligned suspensions for both…
Chirality is a recurrent theme in the study of biological systems, in which active processes are driven by the internal conversion of chemical energy into work. Bacterial flagella, acto-myosin filaments and microtubule bundles are active…
The growing interest in the non-equilibrium assembly of colloidal particles in active liquids is driven by the motivation to create novel structures endowed with tunable properties unattainable within the confines of equilibrium systems.…
We illustrate a concept for shape-changing microswimmers, which exploits the hysteresis of a shape transition of an elastic object, by an elastic disk undergoing cyclic localized swelling. Driving the control parameter of a hysteretic shape…
We theoretically and computationally study the low-Reynolds-number hydrodynamics of a linear active microswimmer surfing on a compressible thin fluid layer characterized by an odd viscosity. Since the underlying three-dimensional fluid is…
Active hydrodynamic theories are a powerful tool to study the emergent ordered phases of internally driven particles such as bird flocks, bacterial suspension and their artificial analogues. While theories of orientationally ordered phases…
When a chiral isotropic elastomer is brought to low temperature cholesteric phase, the nematic degree of freedom tends to order and form a helix. Due to the nemato-elastic coupling, this also leads to elastic deformation of the polymer…
We study how hydrodynamic interactions affect the collective behaviour of active particles suspended in a fluid at high concentrations, with particular attention to lubrication forces which appear when the particles are very close to one…
We study catalytic Janus swimmers and Escherichia coli bacteria swimming in a two-dimensional colloidal crystal. The Janus swimmers orbit individual colloids and hop between colloids stochastically, with a hopping rate that varies inversely…
One of the defining features of active nematics is that above a critical activity the quiescent state becomes unstable to a distorted, flowing one. We show that spatial variations in activity can fundamentally change the nature of this…
Control of physical behaviors of nematic colloids and colloidal crystals has been demonstrated by tuning particle shape, topology, chirality and surface charging. However, the capability of altering physical behaviors of such soft matter…
We show that confining extensile nematics in 3D channels leads to the emergence of two self-organized flow states with nonzero helicity. The first is a pair of braided anti-parallel streams - this double helix occurs when the activity is…
Confining a liquid crystal imposes topological constraints on the orientational order, allowing global control of equilibrium systems by manipulation of anchoring boundary conditions. In this article, we investigate whether a similar…
In isotropic fluids like water, micrometer-scale swimmers have evolved swim strokes to translate despite their tiny size. As described by Purcell in his Scallop Theorem, reciprocal motions, like those performed by a scallop, cannot drive…
We observe novel positional control of a colloidal particle in microchannel flow of a nematic liquid crystal. Lattice Boltzmann simulations show multiple equilibrium particle positions, the existence and position of which are tunable using…
Active fluids are a class of non-equilibrium systems where energy is injected into the system continuously by the constituent particles themselves. Many examples, such as bacterial suspensions and actomyosin networks, are intrinsically…
Active motion at complex fluid-fluid interfaces is a ubiquitous phenomenon in nature. However, an intriguing question that is not fully addressed is how active motion affects and gets influenced by its complex environment. Here, we design a…
When liquid-crystal elastomers are prepared without any alignment, disordered polydomain structures emerge as the materials are cooled into the nematic phase. These polydomain structures have been attributed to quenched disorder in the…
The dynamics of swimming bacteria depend on the properties of their habitat media. Recently it was shown that the motion of swimming bacteria dispersed directly in a non-toxic water-based lyotropic chromonic liquid crystal can be controlled…
Cholesteric liquid crystals can exhibit spatial patterns in molecular alignment at interfaces that can be exploited for particle assembly. These patterns emerge from the competition between bulk and surface energies, tunable with the system…