Latest in cond-mat.soft

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Scaling of wetting and pre-wetting transitions on nano-patterned wallsAug 22 2019We consider a nano-patterned planar wall consisting of a periodic array of stripes of width $L$, which are completely wet by liquid (contact angle $\theta=0$), separated by regions of width $D$ which are completely dry (contact angle $\theta=\pi)$. Using ... More
On the effect of coalescence on the rheology of emulsionsAug 22 2019We present a numerical study of the rheology of a two-fluid emulsion in dilute and semidilute conditions. The analysis is performed for different capillary numbers, volume fraction and viscosity ratio under the assumption of negligible inertia and zero ... More
Mesoscale computational protocols for the design of highly cooperative bivalent macromoleculesAug 22 2019The last decade has witnessed a swiftly increasing interest in the design and production of novel multivalent molecules as powerful alternatives for conventional antibodies in the fight against cancer and infectious diseases. However, while it is widely ... More
Dynamics and stability of a compound particle -- a theoretical studyAug 22 2019Particles confined in droplets are called compound particles. They are encountered in various biological and soft matter systems. Hydrodynamics can play a decisive role in determining the configuration and stability of these multiphase structures during ... More
The Jamming Energy Landscape is Hierarchical and UltrametricAug 22 2019The free energy landscape of mean field marginal glasses is ultrametric. We demonstrate that this feature remains in finite 3 dimensional systems by finding sets of minima which are nearby in configuration space. By calculating the distance between these ... More
Spatial and Temporal fluctuation of an ABP in an optical trapAug 22 2019Active colloidal systems contain active particle, which converts energy from the environment into directed or persistent motion. An outstanding question, debated to date, pertains to how a quantitative and well-defined means can be established to quantify ... More
Method of regularised stokeslets: Flow analysis and improvement of convergenceAug 22 2019Since their development in 2001, regularised stokeslets have become a popular numerical tool for low-Reynolds number flows since the replacement of a point force by a smoothed blob overcomes many computational difficulties associated with flow singularities ... More
Seeing through a glass clearly: Experimental observation of the marginal glass phaseAug 22 2019It has recently been shown that in the infinite dimension mean field limit there exists a second phase transition within the glassy phase, dividing stable glass and marginal glass. We have developed a technique to experimentally probe these phases of ... More
Distinct signature of two local structural motifs of liquid water in the scattering functionAug 21 2019Liquids generally become more ordered upon cooling. However, it has been a long-standing debate on whether such structural ordering in liquid water takes place continuously or discontinuosly: continuum vs. mixture models. Here, by computer simulations ... More
Equilibrium and stability of two-dimensional pinned dropsAug 21 2019Superhydrophobicity relies on the stability of drops's interfaces pinned on sharp edges to sustain non-wetting (Cassie-Baxter) equilibrium states. Gibbs already pointed out that equilibrium is possible as long as the pinning angle at the edge falls between ... More
Apollonian Packing in Polydisperse EmulsionsAug 21 2019We have discovered the existence of polydisperse High Internal-Phase-Ratio Emulsions (HIPE) in which the internal-phase droplets, present at 95% volume fraction, remain spherical and organize themselves in the available space according to Apollonian packing ... More
Non-affinity and fluid-coupled viscoelastic plateau for immersed fiber networksAug 21 2019We employ a matrix-based solver for the linear rheology of fluid-immersed disordered spring networks to reveal four distinct dynamic response regimes. One regime - completely absent in the known vacuum response - exhibits coupled fluid flow and network ... More
Diffusion-influenced reaction rates in the presence of pair interactionsAug 21 2019The kinetics of bimolecular reactions in solution depends, among other factors, on intermolecular forces such as steric repulsion or electrostatic interaction. Microscopically, a pair of molecules first has to meet by diffusion before the reaction can ... More
Vortex Shear Banding Transitions in Superconductors with Inhomogeneous Pinning ArraysAug 20 2019We numerically examine the flow of superconducting vortices in samples containing square pinning arrays in which a band of pins is removed. When a drive is applied at an angle with respect to the band orientation, we find that the vortex depinning initiates ... More
How kinesin waits for ATP affects the nucleotide and load dependence of the stepping kineticsAug 20 2019Dimeric molecular motors walk on polar tracks by binding and hydrolyzing one ATP per step. Despite tremendous progress, the waiting state for ATP binding in the well-studied kinesin that walks on microtubule (MT), remains controversial. One experiment ... More
Topological elasticity of flexible structuresAug 20 2019Flexible mechanical metamaterials possess repeating structural motifs that imbue them with novel, exciting properties including programmability, anomalous elastic moduli and nonlinear and robust response. We address such structures via micromorphic continuum ... More
Theory of Applying Heat Flow from Thermostatted Boundary Walls: Dissipative and Local-Equilibrium Responses and Fluctuation TheoremsAug 20 2019We construct a microscopic theory of applying a heat flow from thermostatted boundary walls in the film geometry. We treat a classical one-component fluid, but our method is applicable to any fluids and solids. We express linear response of any variable ... More
Signature of jamming under steady shear in dense particulate suspensionsAug 20 2019Under an increasing applied shear stress ($\sigma$), viscosity of many dense particulate suspensions increases drastically beyond a stress onset ($\sigma_0$), a phenomenon known as discontinuous shear-thickening (DST). Recent studies point out that some ... More
Experimental demonstration of a dusty plasma ratchet rectification and its reversalAug 20 2019The naturally persistent flow of hundreds of dust particles is experimentally achieved in a dusty plasma system with the asymmetric sawteeth of gears on the electrode. It has also demonstrated that the direction of the dust particle flow can be controlled ... More
A Simulation Algorithm for Brownian Dynamics on Complex Curved SurfacesAug 20 2019Brownian dynamics of colloidal particles on complex surfaces has found important applications in diverse physical, chemical and biological processes. However, current Brownian dynamics simulation algorithms mostly work for relatively simple surfaces that ... More
Ewald summation for ion-dipole mixture under dielectric confinementAug 20 2019A modified 3D-Ewald summation is presented for accurately simulating the ion-dipole mixture under dielectric confinement. The method is based on the combination of image charges and image dipoles with the conventional Ewald summation and has a scaling ... More
Isomorph invariance of dynamics of sheared glassy systemsAug 19 2019We study hidden scale invariance in the glassy phase of the Kob-Andersen binary Lennard-Jones system. After cooling below the glass transition, we generate a so-called isomorph from the fluctuations of potential energy and virial in the NVT ensemble -- ... More
Steady states of non-axial dipolar rods driven by rotating fieldsAug 19 2019We investigate a two-dimensional system of magnetic colloids with anisotropic geometry (rods) subjected to an oscillating external magnetic field. The structural and dynamical properties of the steady states are analyzed, by means of Langevin Dynamics ... More
Stable wrinkling in voltage and charge controlled dielectric membranesAug 19 2019Thin dielectric elastomers with compliant electrodes exhibit various types of instability under the action of electromechanical loading. Guided by the thermodynamically-based formulation of Fosdick and Tang (J. Elasticity 88, 255-297, 2007), here we provide ... More
Epiphoresis: a nonequilibrium mechanism for fast search on DNAAug 19 2019Vital biological processes such as genome repair require fast and efficient binding of selected proteins to specific target sites on DNA. Here we propose an active target search mechanism based on "epiphoresis", the dynamics of DNA-binding proteins up ... More
Multifunctional Composites for Elastic and Electromagnetic Wave PropagationAug 19 2019Composites are ideally suited to achieve desirable multifunctional effective properties, since the best properties of different materials can be judiciously combined with designed microstructures. Here we establish the first cross-property relations for ... More
Threading-Induced Dynamical Transition in Chimeric PolymersAug 19 2019The relationship between polymer topology and bulk rheology remains a key question in soft matter physics. Architecture-specific constraints (or threadings) are thought to control the dynamics of circular polymers in ring-linear blends where the dynamics ... More
The spherical coordinate form of three-dimensional generalized dynamics of soft-matter quasicrystals with 12-fold symmetryAug 19 2019This article reports the spherical coordinate form of three-dimensional generalized dynamics of soft-matter quasicrystals with 12-fold symmetry which provides a basis for solving initial-boundary value problems of the equations under some important cases. ... More
Accelerated relaxation in disordered solids under cyclic loading with alternating shear orientationAug 18 2019The effect of alternating shear orientation during cyclic loading on the relaxation dynamics in disordered solids is examined using molecular dynamics simulations. The model glass was initially prepared by rapid cooling from the liquid state and then ... More
Swarming of micron-sized hematite cubes in a rotating magnetic field -- ExperimentsAug 18 2019Energy input by under-field rotation of particles drives the systems to emergent non-equilibrium states. Here we investigate the suspension of rotating magnetic cubes. Micron-sized hematite cubes are synthesized and observed microscopically. When exposed ... More
Equation Systems of Generalized Hydrodynamics for Soft-Matter QuasicrystalsAug 18 2019The equation systems of generalized hydrodynamics, or generalized dynamics for simplicity, for soft-matter quasicrystals were established. Considering the fluidity of the matter with high order we introduced a new elementary excitation---fluid phonon ... More
Universal features in "stickiness" criteria for soft adhesion with rough surfacesAug 18 2019A very interesting recent paper by Dalvi et al. has demonstrated convincingly with adhesion experiments of a soft material with a hard rough material that the simple energy idea of Persson and Tosatti works reasonably well, namely the reduction in apparent ... More
Nonreciprocal response theory of nonhermitian mechanical metamaterials: response phase transition from the skin effect of zero modesAug 17 2019Nonreciprocal nonhermitian systems provide an unconventional localization mechanism of topological zero modes via the nonhermitian skin effect. While fundamental theoretical characterizations of this effect involve the biorthogonal system of right and ... More
Inertial migration of neutrally-buoyant particles in superhydrophobic channelsAug 17 2019At finite Reynolds numbers particles migrate across flow streamlines to their equilibrium positions in microchannels. Such a migration is attributed to an inertial lift force, and it is well-known that the equilibrium location of neutrally-buoyant particles ... More
Stacking disorder in periodic minimal surfacesAug 17 2019We construct 1-parameter families of non-periodic embedded minimal surfaces of infinite genus in $T \times \mathbb{R}$, where $T$ denotes a flat 2-tori. Each of our families converges to a foliation of $T \times \mathbb{R}$ by $T$. These surfaces then ... More
Liquid-crystal enabled electrophoresis: Scenarios for driving and reconfigurable assembling of colloidsAug 16 2019We demonstrate several examples of driving and steering of colloids when dispersed in nematic liquid crystals. The driving mechanism is based on the principle of nonlinear electrophoresis which is mediated by the asymmetry in the structure of the defects ... More
An exploratory study of the glassy landscape near jammingAug 16 2019We present the study of the landscape structure of athermal soft spheres both as a function of the packing fraction and of the energy. We find that, on approaching the jamming transition, the number of different configurations available to the system ... More
Topotaxis of active Brownian particlesAug 16 2019Recent experimental studies have demonstrated that cellular motion can be directed by topographical gradients, such as those resulting from spatial variations in the features of a micropatterned substrate. This phenomenon, known as topotaxis, is especially ... More
Controlling the transport of active matter in disorderd lattices of asymmetrical obstaclesAug 16 2019We investigate the transport of active matter system in the presence of a disordered square lattice of half-circles, which is built by removing a fraction of them from the initial full lattice. We consider no external field. We observe a spontaneous inversion ... More
$θ$-curves in proteinsAug 16 2019Apart from the knots formed by the main-chain, the proteins can form numerous topological structures, when included the covalent and ion-mediated interactions. In this work, we define the protein non-trivial $\theta$-curves and identify 7 different topologies ... More
Organization of fast and slow chromatin revealed by single-nucleosome dynamicsAug 16 2019Understanding chromatin organization and dynamics is important since they crucially affect DNA functions. In this study, we investigate chromatin dynamics by statistically analyzing single-nucleosome movement in living human cells. Bi-modal nature of ... More
Autonomous navigation of shape-shifting microswimmersAug 16 2019We describe a method for programming the autonomous navigation of active colloidal particles in response to spatial gradients in a scalar stimulus. Functional behaviors such as positive or negative chemotaxis are encoded in the particle shape, which responds ... More
Neural network for phase diagrams of polymer-containing liquid mixturesAug 15 2019Polymer-containing liquid mixtures can exhibit macroscopic phase separation and microphase separation. The diversity of the phase behavior exponentially increases when altering the polymer architecture or adding salt ions, yet exploring and modeling this ... More
Switchable phonon diodes using nonlinear topological Maxwell latticesAug 15 2019Recent progress in topological mechanics have revealed a family of Maxwell lattices that exhibit topologically protected floppy edge modes. These modes lead to a strongly asymmetric elastic wave response. In this paper, we show how topological Maxwell ... More
Using schematic models to understand the microscopic basis for inverted solubility in $γ$D-crystallinAug 15 2019Inverted solubility--a crystal melting upon cooling--is observed in a handful of proteins, such as carbomonoxy hemoglobin and $\gamma$D-crystallin. In human $\gamma$D-crystallin, the phenomenon is associated with the mutation of the 23$^\mathrm{rd}$ residue, ... More
The bending energy of a semi-flexible polymer chain and the polygons of the polymer chainAug 15 2019We consider random walk model of a semi-flexible polymer chain on a square and a cubic lattice to enumerate conformations of the polymer chain in two and three dimensions, respectively. The bending energy of the chain is assumed as the key factor which ... More
Liquid-Hextic-Solid Phase Transition of a Hard-Core Lattice Gas with Third Neighbor ExclusionAug 15 2019The determination of phase behavior and, in particular, the nature of phase transitions in two-dimensional systems is often clouded by finite size effects and by access to the appropriate thermodynamic regime. We address these issues using an alternative ... More
Desalination due to Electrical Image ForcesAug 14 2019It will be shown that for a solution of salt dissolved in water in contact with a metallic wall, the concentration of salt ions (both positive and negative) within a few Angstroms of the wall can be large enough to exceed the solubility limit of the salt, ... More
Random sequential adsorption of spheres on a cylinderAug 14 2019Inspired by observations of beads packed on a thin string in such systems as sea-grapes and dental plaque, we study the random sequential adsorption of spheres on a cylinder. We determine the asymptotic fractional coverage of the cylinder as a function ... More
Quenched Dynamics of Artificial Spin Ice: Coarsening versus Kibble-ZurekAug 14 2019Artificial spin ices are ideal frustrated model systems in which to explore or design emergent phenomena with unprecedented characterization of the constituent degrees of freedom. In square spin ice, violations of the ice rule are topological excitations ... More
Analysis of granular rheology in a quasi-two-dimensional slow flow by means of discrete element method based simulationsAug 14 2019The steady flow of spherical particles in a rectangular bin is studied using the Discrete Element Method (DEM) for different flow rates of the particles from the bin, in the slow flow regime. The flow has two non-zero velocity components and is more complex ... More
A Tuneable Magnetic Domain Wall Conduit Regulating Nanoparticle DiffusionAug 14 2019We demonstrate a general and robust method to confine on a plane strongly diffusing submicrometer particles in water by using size tunable magnetic channels. These virtual conduits are realized with pairs of movable Bloch walls (BWs) located within an ... More
Rivalry of diffusion, external field and gravity in micro-convection of magnetic colloidsAug 14 2019Magnetic fields and magnetic materials have promising microfluidic applications. For example, magnetic micro-convection can enhance mixing considerably. However, previous studies have not explained increased effective diffusion during this phenomenon. ... More
Recent progress towards chemically-specific coarse-grained simulation models with consistent dynamical propertiesAug 14 2019Coarse-grained (CG) models can provide computationally efficient and conceptually simple characterizations of soft matter systems. While generic models probe the underlying physics governing an entire family of free-energy landscapes, bottom-up CG models ... More
The non-homogeneous flow of a thixotropic fluid around a sphereAug 14 2019The non-homogeneous flow of a thixotropic fluid around a settling sphere is explored. A four-parameter Moore model is used for a generic thixotropic fluid and discontinuous Galerkin method is employed to solve the structure-kinetics equation coupled with ... More
Detachment of fluid membrane from substrate and vesiculationAug 14 2019The detachment dynamics of a fluid membrane with an isotropic spontaneous curvature from a flat substrate are studied by using meshless membrane simulations. The membrane is detached from an open edge leading to vesicle formation. With strong adhesion, ... More
Random walk on a lattice in the presence of obstacles: The short-time transient regime, anomalous diffusion and crowdingAug 14 2019The diffusion of a particle in a crowded environment typically proceeds through three regimes: for very short times the particle diffuses freely until it collides with an obstacle for the first time, while for very long times diffusion the motion is Fickian ... More
Steady state cyclic behaviour of a half-plane contact in partial slip subject to varying normal load, moment, shear load, and moderate differential bulk tensionAug 13 2019A new solution for a general half-plane contact in the steady state is presented. The contacting bodies are subject to a set of constant loads - normal force, shear force and bulk tension parallel with the interface - together with an oscillatory set ... More
Resolving a controversy about adhesion in sliding contactsAug 13 2019An interesting recent paper by Menga, Carbone & Dini (MCD, 2018, [1]), suggests that in sliding adhesive contacts, the contact area should increase due to tangential shear stresses at the interface, assumed to be constant and corresponding to a material ... More
End-to-End Machine Learning for Experimental Physics: Using Simulated Data to Train a Neural Network for Object Detection in Video MicroscopyAug 13 2019We demonstrate a method for training a convolutional neural network with simulated images for usage on real-world experimental data. Modern machine learning methods require large, robust training data sets to generate accurate predictions. Generating ... More
The range of geometrical frustration in lattice spin modelsAug 12 2019The concept of geometrical frustration in condensed matter physics refers to the fact that a system has a locally preferred structure with an energy density lower than the infinite ground state. This notion is however often used in a qualitative sense ... More
Co-assembly of Janus nanoparticles in block copolymer systemsAug 12 2019Block copolymer are ideal matrices to control the localisation of colloids. Furthermore, anisotropic nanoparticles such as Janus nanoparticles possess an additional orientational degree of freedom that can play a crucial role in the formation of highly ... More
Surface oscillations and breakup characteristics of a charged droplet in the presence of various time varying functionsAug 12 2019A charged droplet can be levitated in the air when suspended in a trap subjected to quadrupole potential. The applied potential is typically sinusoidal. Such a charged drop undergoes surface oscillations subsequently building enough charge density to ... More
Surface oscillations and breakup characteristics of a charged droplet in the presence of various time varying functionsAug 12 2019Aug 15 2019A charged droplet can be levitated in the air when suspended in a trap subjected to quadrupole potential. The applied potential is typically sinusoidal. Such a charged drop undergoes surface oscillations subsequently building enough charge density to ... More
Tuning the random walk of active colloidsAug 12 2019Active particles such as swimming bacteria or self-propelled colloids are known to spontaneously organize into fascinating large-scale dynamic structures. The emergence of these collective states from the motility pattern of the individual particles, ... More
On the inflation and deflation dynamics of liquid-filled, hyperelastic balloonsAug 12 2019We derive a reduced-order model describing the inflation and deflation dynamics of a liquid-filled hyperelastic balloon, focusing on inviscid laminar flow and the extensional motion of the balloon. We initially study the flow and pressure fields for dictated ... More
The assembly of freely moving rigid fibers measures the flow velocity gradient tensorAug 12 2019The motion of an assembly of rigid fibers is investigated for different classes of closed streamline flows, steady or time dependent, two dimensional or three dimensional. In our study, the dynamics of the fiber assembly is fully-coupled to the flow field ... More
Linker-mediated self-assembly of mobile DNA coated colloidsAug 12 2019An immense challenge in materials science is to find a way to construct materials with absolute control over the placement of each building block in order to tailor properties for given applications. In past decades, DNA coated colloids offer the possibility ... More
Microparticle transport networks with holographic optical tweezers and cavitation bubblesAug 12 2019Optical transport networks for active absorbing microparticles are made with holographic optical tweezers. The particles are powered by the optical potentials that make the network and transport themselves via random vapor propelled hops to different ... More
A computational study of transient shear banding in soft jammed solidsAug 11 2019We have designed 3D numerical simulations of a soft spheres model, with size polidispersity and in athermal conditions, to study the transient shear banding that occurs during yielding of jammed soft solids. We analyze the effects of different types of ... More
Influence of non-hydrodynamic forces on the elastic response of an ultra-thin soft coating under fluid-mediated dynamic loadingAug 11 2019The force between two approaching solids in a liquid medium becomes increasingly large with decreasing separation, a phenomenon that prevents contact between the two solids. This growth in force occurs because of the intervening liquid, and, studies of ... More
Quantitative Assessment of the Toner and Tu Theory of Polar FlocksAug 10 2019We present a quantitative assessment of the Toner and Tu theory describing the universal scaling of fluctuations in polar phases of dry active matter. Using large scale simulations of the Vicsek model in two and three dimensions, we find the overall phenomenology ... More
Implementation of Morse-Witten theory for a polydisperse wet 2D foam simulationAug 10 2019The Morse-Witten theory (D. Morse and T. Witten, EPL 22 (1993) 549-555) provides a formulation for the inter-bubble forces and corresponding deformations in a liquid foam, accurate in the limit of high liquid fraction. Here we show how the theory may ... More
Loops versus lines and the compression stiffening of cellsAug 10 2019Both animal and plant tissue exhibit a nonlinear rheological phenomenon known as compression stiffening, or an increase in moduli with increasing uniaxial compressive strain. Does such a phenomenon exist in single cells, which are the building blocks ... More
Dynamic Force Measurements on Swimming Chlamydomonas Cells using Micropipette Force SensorsAug 09 2019Flagella and cilia are cellular appendages that inherit essential functions of microbial life including sensing and navigating the environment. In order to propel a swimming microorganism they displace the surrounding fluid by means of periodic motions, ... More
Theory of the flow-induced deformation of shallow compliant microchannels with thick wallsAug 09 2019Long, shallow microchannels embedded in thick soft materials are widely used in microfluidic devices for lab-on-a-chip applications. However, the bulging effect caused by fluid--structure interactions between the internal viscous flow and the soft walls ... More
Many-body correlations from integral geometryAug 09 2019In a recent letter we presented a framework for predicting the concentrations of many-particle local structures inside the bulk liquid as a route to assessing changes in the liquid approaching dynamical arrest. Central to this framework was the morphometric ... More
Extreme-Value Statistics of Molecular MotorsAug 09 2019We derive exact expressions for the finite-time statistics of extrema (maximum and minimum) of the spatial displacement and the fluctuating entropy flow of biased random walks modelling the dynamics of molecular motors at the single-molecule level. Our ... More
Capillary action in scalar active matterAug 09 2019We study the capacity of active matter to rise in thin tubes against gravity and other related phenomena, like, wetting of vertical plates and spontaneous imbibition, where a wetting liquid is drawn into a porous medium. This capillary action or capillarity ... More
Artificial Spin Ice of Liquid Crystal SkyrmionsAug 08 2019A push to generate exotic, emergent phenomena in the collective behavior of simple, interacting, artificial building blocks proved successful using nano magnets, confined micro-colloids, or superconducting vortices as platforms to realize so-called artificial ... More
Effect of trap potential on the Rayleigh breakup of a levitated charged dropletAug 08 2019Rayleigh instability that results in the breakup of a charged droplet, levitated in a quadrupole trap, has been investigated in the literature, but only scarcely. We report here asymmetric breakup of a charged drop, levitated in a loose trap, wherein, ... More
Geometrical structure and thermal conductivity of dust aggregates formed via ballistic cluster-cluster aggregationAug 08 2019We herein report a theoretical study of the geometrical structure of porous dust aggregates formed via ballistic cluster-cluster aggregation (BCCA). We calculated the gyration radius $R_{\rm gyr}$ and the graph-based geodesic radius $R_{\rm geo}$ as a ... More
Nondiffusive Fluxes in Brownian System with Lorentz ForceAug 08 2019The Fokker-Planck equation provides complete statistical description of a particle undergoing random motion in a solvent. In the presence of Lorentz force due to an external magnetic field, the Fokker-Planck equation picks up a tensorial coefficient, ... More
Heterogeneity of polymer network micro-regions as formed by end-linking processesAug 08 2019Polymerization and formation of crosslinked polymer networks are important processes in manufacturing, materials fabrication, and in the case of hydrated polymer networks, biomedical materials, drug delivery, and tissue engineering applications. While ... More
Localized Transient Jamming in Discontinuous Shear ThickeningAug 07 2019Aug 16 2019We report direct measurements of spatially resolved surface stresses over the entire surface of a dense suspension during discontinuous shear thickening (DST) using Boundary Stress Microscopy (BSM) in a parallel-plate rheometer. We find that large fluctuations ... More
Localized Transient Jamming in Discontinuous Shear ThickeningAug 07 2019We report direct measurements of spatially resolved surface stresses over the entire surface of a dense suspension during discontinuous shear thickening (DST) using Boundary Stress Microscopy (BSM) in a parallel-plate rheometer. We find that large fluctuations ... More
Spatiotemporal dynamics of frictional systems: The interplay of interfacial friction and bulk elasticityAug 07 2019Frictional interfaces are abundant in natural and engineering systems, and predicting their behavior still poses challenges of prime scientific and technological importance. At the heart of these challenges lies the inherent coupling between the interfacial ... More
Shear Destruction of Frictional Aging and MemoryAug 07 2019We simultaneously measure the static friction and the real area of contact between two solid bodies. Under static conditions both quantities increase logarithmically in time, a phenomenon coined aging. Indeed, frictional strength is traditionally considered ... More
A Practical Mini-Course on Applied HolographyAug 07 2019This is a collection of notes based on lectures that will be given at IIT Madras in September 2019. It is supposed to be a concise (and therefore not comprehensive) and pragmatic course on applied holography and especially the (basic) analytic and numerical ... More
Deformation of flexible ferromagnetic filaments under a rotating magnetic fieldAug 07 2019Research on magnetic particles dispersed in a fluid medium, actuated by a rotating magnetic field, is becoming increasingly active for both lab-on-chip and bio-sensing applications. In this study, we experimentally investigate the behaviour of ferromagnetic ... More
Lorentz forces induce inhomogeneity and fluxes in active systemsAug 07 2019We consider the nonequilibrium dynamics of a charged active Brownian particle in the presence of a space dependent magnetic field. It has recently been shown that the Lorentz force induces a particle flux perpendicular to density gradients, thus preventing ... More
Deriving phase field crystal theory from dynamical density functional theory: consequences of the approximationsAug 07 2019Phase field crystal (PFC) theory, extensively used for modelling the structure of solids, can be derived from dynamical density functional theory (DDFT) via a sequence of approximations. Standard derivations neglect a term of form $\nabla\cdot[n\nabla ... More
BoltzmaNN: Deriving effective pair potentials and equations of state using neural networksAug 07 2019In this work we investigate the use of neural networks (NNs) to devise effective equations of state from a given isotropic pair potential using the virial expansion of the pressure. We train the NNs with data from molecular dynamics simulations, sampled ... More
Infinitesimal asphericity changes the universality of the jamming transitionAug 06 2019The jamming transition of nonspherical particles is fundamentally different from the spherical case. Systems of nonspherical particles are hypostatic at the jamming point, while isostaticity is ensured in the case of the jamming of spherical particles. ... More
Continuous time random walk concepts applied to extended mode coupling theory: A study of the Stokes-Einstein breakdownAug 06 2019In an attempt to extend the mode coupling theory (MCT) to lower temperatures, an Unified theory was proposed which within the MCT framework incorporated the activated dynamics via the random first order transition theory (RFOT). Here we show that the ... More
Divining the Shape of Nascent Polymer Crystal NucleiAug 05 2019We demonstrate that nascent polymer crystals (i.e., nuclei) are anisotropic entities, with neither spherical nor cylindrical geometry, in contrast to previous assumptions. In fact, cylindrical, spherical, and other high symmetry geometries are thermodynamically ... More
Strain softening and stiffening responses of spider silk fibers probed using Micro-Extension RheometerAug 05 2019Spider silk possesses unique mechanical properties like large extensibility, high tensile strength, super-contractility, etc. Understanding these mechanical responses require characterization of the rheological properties of silk beyond the simple force-extension ... More
Mixing-Demixing Transition in Polymer-Grafted Spherical NanoparticlesAug 05 2019Polymer-grafted nanoparticles can provide property profiles than cannot be obtained individually by polymers or nanoparticles. Here, we have studied the order--disorder transition of symmetric copolymer melts of polymer-grafted nanoparticles with spherical ... More
Streaming Potential in Bio-mimetic Microvessels Mediated by Capillary GlycocalyxAug 05 2019Implantable medical devices and biosensors are pivotal in revolutionizing the field of medical technology by opening new dimensions in the field of disease detection and cure. These devices need to harness a biocompatible and physiologically sustainable ... More
Characterizing the mesh size of polymer solutions via the pore size distributionAug 05 2019In order to characterize the geometrical mesh size $\xi$, we simulate a solution of coarse-grained polymers with densities ranging from the dilute to the concentrated regime and for different chain lengths. Conventional ways to estimate $\xi$ rely either ... More