Research

High fidelity ion selectivity in Electric Eel-inspired power sources to maximize power density and discharge duration: a computational and experimental tuning of interfacial transport. 

This project addresses a critical challenge in energy storage: designing soft, biocompatible power sources, specifically those inspired by mimicking the anatomy of electric eels, which currently suffer from low performance. The power that that electric eel provides is insufficient to power a device, for example, an LED valve. Torpedo rays help to overcome these limitations, as electrocytes are arranged in both series (improving voltage) and parallel (improving current) connections instead of only in series arrangements of electrocytes like electric eel fish. Salinity gradients across selective hydrogel layers are used by these bio-inspired cells to produce energy, but careful control over ion transport is necessary to provide reliable output. Still, there is a huge difference between the performance of artificial organs and electric eels. One of the main reasons behind this difference is that contact resistance is high for artificial organs. To reduce the contact resistance, we need to reduce the thickness of hydrogels more. In our lab, we used the layer-by-layer spin coating method to develop an ultrathin layer of power stack, which is comparable to biological organ dimension and provides more power. The power stacks consist of five layers of hydrogels following High Salinity, cation selective, low salinity, anion selective, and high salinity order to generate power. Cation and Anion passing through the cation and anion-selective layers, respectively, provides charge separation in the low-salinity layer generating voltage. The major problem of this power system is that the self-discharge rate is too high once the assembly is formed, which limits the usage of this for a longer period of time. The main aim of my work is to achieve high-fidelity ion selectivity and maximize key performance indicators such as power density and discharge duration. This study uses interfacial transport tuning to overcome inherent material and architectural inefficiencies in the selective layers, making the technology viable for flexible and bio-integrated applications. 

THESIS: Mechanical Characteristics of Crumpled Graphene Electrode Under Uniaxial Dynamic Tensile Loading using Molecular Dynamics Approach.

Software USED: LAMMPS, MS EXCEL, OVITO, MATLAB, Tecplot 360 

In this study, the mechanical response of crumpled graphene (CG) with different magnitudes of crumpling and porosity to tensile loading has been investigated by molecular dynamics simulation. A single graphene sheet (5 nm x 5 nm) is crumpled and stabilized for creating the CG structure, a 3D nanomaterial with higher surface area, and conductivity. Initially, compared to flat graphene, crumpling in CG electrodes causes a considerable decrease in both fracture toughness and elastic modulus up to a specific radius. These mechanical properties do, however, get better with a higher degree of crumpling. A fall of 24% in fracture toughness and a 30% reduction in elastic modulus are observed as the crumpling radius reduces from 26.5 Å to 19.3 Å. Although the mechanical performance of CG is adversely affected by even a small amount of porosity, this reduction is largely offset by higher crumpling, especially at smaller radii. Porous CG electrodes show almost the same strength as their non-porous counterparts at lower radii, where crumpling is more prominent. The anisotropy in the CG structure is examined by applying load along all three axes, and the variation of strain energy in non-porous CG during deformation is analyzed. The effect of compressive load (for a crumpling radius of 7.6 Å) and the morphological structure of the system on the mechanical behavior of crumpled graphene is also explored and reported.