arXiv subjects

Vinitha Johny

Publications and source records attributed to Vinitha Johny.

3 recordsLinked to original sources

arXiv2023

Active solid-state nanopores: Self-driven flows/chaos at liquid-gas nanofluidic interface

We present a study of self-driven flow dynamics at the liquid-gas interface within nanofluidic pores, devoid of any external driving forces. The investigation centres on the Rayleigh-Taylor instability phenomena occurring in sub-100 nanometre-scale fluidic pores situated within a micrometer-scale water and air domain. This research rigorously validates our flow velocity equation using simulation results while delving into the mass transfer efficiency of these intricate flow structures. Notably, we introduce a concept - an 'active solid-state nanopore' - that exhibits self-driven flow switching behaviour, transitioning between active and passive states without the need for mechanical components. This study reveals highly nonlinear and complex fluid dynamics within nanoscale dimensions, marking an exploration in this domain at room temperature. Implications of self-driven nanofluidics extend across diverse fields, from enhancing biosensors and healthcare applications to advancing net-zero sustainable energy production and contributing to the fundamental understanding of fluid dynamics in confined spaces.

physics.flu-dyn↗

arXiv2022

Superfluidic nature of self-driven nanofluidics at liquid-gas interfaces

Self-driven nanofluidic flow at the liquid-air interface is a non-intuitive phenomenon. This flow behaviour was not driven by classical pressure difference or evaporation only. Depending on the position of the nanofluidic pore we can observe flow and no-flow with chaotic behaviour. In this paper, we study the nonlinear dynamics of a confined nanopore system at the liquid-air interface. The finite-range interactions between the interacting species are quantified with a corresponding critical velocity of the system. This is visualised using the finite element method and analysed mathematically with the Landau criterion. We found the formation of Bose-Einstein-like condensates due to the transport through nanofluidic pores. We show that systems with more than one nanofluidic pore with a sub-100 nm diameter create a highly nonlinear and complex. The approximation of relevant classical systems to existing quantum mechanical systems divulges new results and corrections at a fundamental level. We explain the formation of oscillating condensate within the system in the liquid phase. The high velocity near the specific boundaries of the system, the sudden disappearance of oscillations, and its dependence on evaporation are explored. This transition of classical mechanics with the outlook of quantum mechanics leaves several open questions for further investigation in the field of quantum nanofluidics.

quant-ph↗

arXiv2021

Towards real-time oxygen sensing: From nanomaterials to plasma

A significantly large scope is available for the scientific and engineering developments of high-throughput ultra-high sensitive oxygen sensors. We give a perspective of oxygen sensing for two physical states of matters - solid-state nanomaterials and plasma. From single-molecule experiments to material selection, we reviewed various aspects of sensing, such as capacitance, photophysics, electron mobility, response time, and a yearly progress. Towards miniaturisation, we have highlighted the benefit of lab-on-chip-based devices and showed exemplary measurements of fast real-time oxygen sensing. From the physical-chemistry perspective, plasma holds a strong potential in the application of oxygen sensing. We investigated the current state-of-the-art of electron density, temperature, and design issues of plasma systems. We also show a numerical aspects of low-cost approach towards developing plasma-based oxygen sensor from household candle flame. In this perspective, we give an opinion about a diverse range of scientific insight together, identifies the short comings, and opens the path for new physical-chemistry device developments of oxygen sensor along with providing a guideline for innovators in oxygen sensing.

physics.chem-ph↗