arXiv subjects

Sergi G. Leyva

Publications and source records attributed to Sergi G. Leyva.

5 recordsLinked to original sources

arXiv2026

Active Ionic Fluxes Induce Symmetry Breaking in Charge-Patterned Nanochannels

Biological systems rely on autonomous modes of charge transport to transmit signals. Instead, conventional synthetic systems typically depend on external fields, such as voltage or pressure gradients, to induce transport, which limits their applicability. Here, we investigate nanochannels in which an electrolyte is confined by symmetric boundary patterns combining surface charge and active ionic fluxes. We show that the interplay between diffusion, electrostatics, and hydrodynamics in such nano-confined active-charged systems can trigger symmetry breaking above a critical active flux, leading to directed flow. Our results suggest that active-charged nanochannels can generate net flows of the order of hundreds of millimeters per second, opening pathways toward adaptable ionic devices and neuromorphic architectures.

cond-mat.soft↗

arXiv2024

Capillary imbibition in lubricant coated channels

Capillary imbibition underpins many processes of fundamental and applied relevance in fluid mechanics. A limitation to the flow is the coupling to the confining solid, which induces friction forces. Our work proposes a general theoretical framework for the modeling of the transport of liquids in lubricant impregnated surfaces. We show that for sufficiently small lubricant viscosity, dissipation entirely occurs in the lubricant layer, resulting in a linear growth of the advancing front. As a result, an external force gives rise to an exponential front growth. This new capacity to control multiphase flows sets new experimental challenges that can be determinant for micro and nanofluidic devices.

physics.flu-dyn↗

arXiv2024

Clogging transition and anomalous transport in driven suspensions in a disordered medium

We study computationally the dynamics of forced, Brownian particles through a disordered system. As the concentration of mobile particles and/or fixed obstacles increase, we characterize the different regimes of flow and address how clogging develops. We show that clogging is preceded by a wide region of anomalous transport, characterized by a power law decay of intermittent bursts. We analyze the velocity distribution of the moving particles and show that this abnormal flow region is characterized by a coexistence between mobile and arrested particles, and their relative populations change smoothly as clogging is approached. The comparison of the regimes of anomalous transport and clogging with the corresponding scenarios of particles pushed through a single bottleneck show qualitatively the same trends highlighting the generality of the transport regimes leading to clogging.

cond-mat.soft↗

arXiv2024

Discontinuous transition in electrolyte flow through charge-patterned nanochannels

We investigate the flow of an electrolyte through a rigid nanochannel decorated with a surface charge pattern. Employing lattice Boltzmann and dissipative particle dynamics methods, as well as analytical theory, we show that the electro-hydrodynamic coupling leads to two distinct flow regimes. The accompanying discontinuous transition between slow, ionic, and fast, Poiseuille flows is observed at intermediate ion concentrations, channel widths, and electrostatic coupling strengths. These findings indicate routes to design nanochannels containing a typical aqueous electrolyte that exhibit a digital on/off flux response, which could be useful for nanofluidics and ionotronic applications.

cond-mat.soft↗

arXiv2023

Hydrodynamics is Needed to Explain Propulsion in Chemophoretic Colloidal Rafts

Active particles driven by a chemical reaction are the subject of intense research to date due to their rich physics, being intrinsically far from equilibrium, and their multiple technological applications. Recent attention in the field is now shifting towards exploring the fascinating dynamics of mixture of active and passive systems. Here we realize active colloidal rafts, composed of a single catalytic particle encircled by several shells of passive microspheres assembled via light activated, chemophoretic flow. We show that considering only diffusiophoresis can explain the cluster kinetics but not the cluster propulsion behavior. Thus, using the Lorenz reciprocal theorem, we show that propulsion emerges by considering hydrodynamics via the diffusioosmotic answer of the substrate to the generated chemophoretic flow. While diffusioosmotic flows are often relegate to a secondary role, our work demonstrates their importance to understand the rich physics of active catalytic systems.

cond-mat.soft↗