A5100620114- Nonlocal and gradient elasticity in micro/nano structures
- Advanced Sensor and Energy Harvesting Materials
- Composite Material Mechanics
- Ferroelectric and Piezoelectric Materials
- Force Microscopy Techniques and Applications
- Advanced Materials and Mechanics
- Dielectric materials and actuators
- Innovative Energy Harvesting Technologies
- Microstructure and mechanical properties
- Electronic Packaging and Soldering Technologies
- Lipid Membrane Structure and Behavior
- Graphene research and applications
- Carbon Nanotubes in Composites
- Numerical methods in engineering
- Aluminum Alloys Composites Properties
- Multiferroics and related materials
- Thermal properties of materials
- Mechanical and Optical Resonators
- Vibration Control and Rheological Fluids
- Semiconductor materials and devices
- Antenna Design and Analysis
- 2D Materials and Applications
- Advancements in Battery Materials
- Advancements in Semiconductor Devices and Circuit Design
- Vibration and Dynamic Analysis
University of Houston
2016-2025
Graphic Era University
2025
Nepal Development Research Institute
2024
Calhoun Community College
2024
Indian Institute of Technology Delhi
2023
Dr. K.N.Modi University
2021
Material (Belgium)
2019-2020
Jaypee Institute of Information Technology
2017
University of Engineering & Management
2017
Indian Institute of Technology Jodhpur
2017
Abstract Two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such ferroelectricity in the 2D limit not been well explored. Here, we report room-temperature CuInP 2 S 6 (CIPS) with a transition temperature of ∼320 K. Switchable polarization is observed thin CIPS ∼4 nm. To demonstrate potential this ferroelectric...
The effect of surface energies, strains, and stresses on the size-dependent elastic state embedded inhomogeneities are investigated. At nanolength scales, due to increasing surface-to-volume ratio, effects become important induce a size dependency in otherwise size-independent classical elasticity solutions. In this letter, closed-form expressions derived for eigenstrained spherical with using variational formulation. Our results indicate that can significantly alter fundamental nature...
Crystalline piezoelectric dielectrics electrically polarize upon application of uniform mechanical strain. Inhomogeneous strain, however, locally breaks inversion symmetry and can potentially even nonpiezoelectric (centrosymmetric) dielectrics. Flexoelectricity---the coupling strain gradient to polarization---is expected show a strong size dependency due the scaling gradients with structural feature size. In this study, using combination atomistic theoretical approaches, we investigate...
The classical formulation of Eshelby (Proc. Royal Society, A241, p. 376, 1957) for embedded inclusions is revisited and modified by incorporating the previously excluded surface/interface stresses, tension energies. latter effects come into prominence at inclusion sizes in nanometer range. Unlike result, our renders elastic state an size-dependent making possible extension Eshelby’s original formalism to nano-inclusions. We present closed-form expressions tensor spherical cylindrical...
In a piezoelectric material, an applied uniform strain can induce electric polarization (or vice versa). Crystallographic considerations restrict this technologically important property to noncentrosymmetric systems. It has been shown both mathematically and physically that nonuniform potentially break the inversion symmetry in nonpiezoelectric materials. The coupling between gradients polarization, conversely gradients, is investigated work. While conventional nonzero only for certain...
Upon application of a uniform strain, internal sub-lattice shifts within the unit cell non-centrosymmetric dielectric crystal result in appearance net dipole moment: phenomenon well known as piezoelectricity. A macroscopic strain gradient on other hand can induce polarization dielectrics any structure, even those which possess centrosymmetric lattice. This phenomenon, called flexoelectricity, has both bulk and surface contributions: strength contribution be characterized by means material...
The ability of certain materials to convert electrical stimuli into mechanical deformation, and vice versa, is a prized property. Not surprisingly, applications such so-called piezoelectric are broad—ranging from energy harvesting self-powered sensors. In this perspective, written in the form question-answers, we highlight relatively understudied electromechanical coupling called flexoelectricity that appears have tantalizing implications topics ranging biophysics design next-generation...
Hydrogels are an extraordinary soft matter system that serve as a laboratory for rich plethora of multiphysical phenomena and find applications range from biocompatible sensors to robots. Here, we report peculiar experimental observation suggesting concurrent stiffening softening in hydrogels during the dehydration process. Theories based on Flory's work fail capture scaling mechanical behavior with water content, observed our experiments. We perform coarse-grained molecular dynamics...
Several exotic characteristics and properties have made graphene a well-studied material from both basic science viewpoint as well tantalizing applications ranging nanoelectronics, gas separation membranes to ultracapacitors. Graphene, however, is non-piezoelectric. This obvious when in its metallic or semi-metallic state. However, even dielectric form—which can be engineered through porosity by using nanoribbons—graphene non-piezoelectric due centrosymmetric crystal structure. Using quantum...
Abstract: In this paper we show that experimentally realizable apparently piezoelectric thin-film super-lattices can be created from non-piezoelectric materials provided an odd-order (e.g. trilayer) stacking sequence is used. The size-dependent mechanism of flexoelectricity, which couples gradients strain to polarization, allows such a possibility. We present closed-form analytical expressions for the response various and super-lattice configurations. also clarify some subtleties arise in...
At what characteristic length scale does classical continuum elasticity cease to accurately describe small deformation mechanical behavior? The two dominant physical mechanisms that lead size dependency of elastic behavior at the nanoscale are surface energy effects and nonlocal interactions. latter arises due discrete structure matter fluctuations in interatomic forces smeared out within phenomenological modulus coarser sizes. While have been well characterized literature, little is known...
Recent work suggests that flexoelectricity causes significant enhancement of electromechanical coupling nonuniformly strained piezoelectric and nonpiezoelectric nanostructures below a material-dependent length scale. In the present work, employing an atomistically informed dynamical continuum model accounts for flexoelectricity, we argue in narrow range geometric dimensions, can dramatically enhance energy harvesting. Specifically, case lead zirconate titanate (PZT) material employed form...
Conventional wisdom suggests that decreasing dimensions of dielectric materials (e.g., thickness a film) should yield increasing capacitance. However, the quantum capacitance and so-called "dead-layer" effect often conspire to decrease extremely small nanostructures, which is in sharp contrast what expected from classical electrostatics. Very recently, first-principles studies have predicted nanocapacitor made graphene hexagonal boron nitride (h-BN) films can achieve superior capacitor...
In this work, using a combination of theoretical framework and atomistic calculations, we highlight the concept “surface piezoelectricity,” which can be used to interpret piezoelectricity nanostructures. Focusing on three specific material systems (ZnO, SrTiO3, BaTiO3), discuss renormalization apparent piezoelectric behavior at small scales. rather interesting interplay symmetry surface effects, show that nanostructures certain non-piezoelectric materials may also exhibit behavior. Finally,...
Abstract Since graphene, a variety of 2D materials have been fabricated in quest for tantalizing combination properties and desired physiochemical behavior. that are piezoelectric, i.e., allow facile conversion electrical energy into mechanical vice versa, offer applications sensors, actuators, harvesting, stretchable flexible electronics, storage, among others. Unfortunately, must satisfy stringent symmetry requirements to be classified as piezoelectric. Here, ultrathin single‐crystal...