A5056143612- Adhesion, Friction, and Surface Interactions
- Force Microscopy Techniques and Applications
- Advanced Materials and Mechanics
- Metal and Thin Film Mechanics
- Ultrasonics and Acoustic Wave Propagation
- Advanced Sensor and Energy Harvesting Materials
- Mechanical stress and fatigue analysis
- Numerical methods in engineering
- High-Velocity Impact and Material Behavior
- Microstructure and mechanical properties
- Mechanical Behavior of Composites
- Optical measurement and interference techniques
- Ion-surface interactions and analysis
- Fatigue and fracture mechanics
- Structural Analysis and Optimization
- Non-Destructive Testing Techniques
- Graphene research and applications
- Semiconductor materials and devices
- Copper Interconnects and Reliability
- Metal Forming Simulation Techniques
- Electrostatic Discharge in Electronics
- Carbon Nanotubes in Composites
- Iron Metabolism and Disorders
- Nonlocal and gradient elasticity in micro/nano structures
- Elasticity and Material Modeling
Samsung (South Korea)
2022-2024
Brown University
2013-2024
John Brown University
1996-2023
Jeonbuk National University
2004-2020
Chosun University
2002-2018
Chonbuk National University Hospital
2011-2018
Google (United States)
2013-2018
Jeonju University
2018
Government of the Republic of Korea
2018
Kyungpook National University
2014
A novel diamagnetic lateral force calibrator (D-LFC) has been developed to directly calibrate atomic microscope (AFM) cantilever-tip or -bead assemblies. This enables an AFM accurately measure the forces encountered in friction biomechanical-testing experiments at a small length scale. In process of development, deformation characteristics cantilever assemblies under frictional loading have analyzed and four essential response variables, i.e., constants, assembly identified. Calibration...
Analyses have been made to extract the objective interfacial fracture toughness from peel strength of very thin metallic films. An elastoplastic bending model adherend film has employed in analyses applying mechanics concept steady-state crack growth. The analytic result finally shown is a universal diagram where readily readable when known. Experimental results for Cu films on Si and polyimide substrate systems with Cr interface are also presented.
We present the mechanics of folding surface-layer wrinkles on a soft substrate, i.e. inter-touching neighbouring wrinkle surfaces without forming cusp. Upon laterally compressing stiff layer attached finite-elastic certain material nonlinearities trigger number bifurcation processes to form multi-mode clusters. Some these clusters eventually develop into folded wrinkles. The first is investigated by perturbation analysis buckling pre-stretched neo-Hookean substrate. post-buckling equilibrium...
We present a simple two-step method to fabricate dual-scale superhydrophobic surfaces by using replica molding of poly(dimethylsiloxane) (PDMS) micropillars, followed deposition thin, hard coating layer SiOx-incorporated diamond-like carbon (DLC). The resulting surface consists microscale PDMS pillars covered nanoscale wrinkles that are induced residual compressive stress the DLC and difference in elastic moduli between without any external stretching or thermal contraction on substrate....
A new transverse-displacement inteferometer (TDI) is described. This interferometer makes use of intensity variations a beam obtained by superposition two beams diffracted symmetrically from diffraction grating copied onto plane surface. The TDI used to monitor the transverse motion rear surface y-cut quartz target plate in plate-impact experiment. For this application, 200-line/mm plate. normal monitored means standard Michelson which zeroth-order as reflected moving mirror. simultaneously...
A micromechanical dislocation model of frictional slip between two asperities is presented. The suggests that when the contact radius smaller than a critical value, friction stress constant, order theoretical shear strength, in agreement with reported atomic force microscope (AFM) experiments. However, at value there transition beyond which decreases increasing area, until it reaches second where gradually becomes independent size. This contrast to previous theories, assume always present...
We present mechanics of surface creasing caused by lateral compression a nonlinear neo-Hookean solid surface, with its elastic stiffness decaying exponentially depth. Nonlinear bifurcation stability analysis reveals that surfaces can develop instantaneous under compressive strains greater than 0.272 but less 0.456. It is found set off when the strain large enough, and longest-admissible perturbation wavelength relative to decay length modulus shorter critical value. A smaller only trigger...
In this study, a novel composite of Cu–Al layered double hydroxide (LDH) nanosheets and g-C<sub>3</sub>N<sub>4</sub>-covered Ni-foam was fabricated <italic>via</italic> simple facile two-step process.
Herein, we report a drug eluting scaffold composed of composite nanofibers poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) loaded with Hydroxyapatite nanoparticles (HANPs) simvastatin (SIM) mimicking the bone extracellular matrix (ECM) to improve cell proliferation regeneration process. Indeed, addition PGS results in slight increase average fiber diameter compared PCL. However, presence HANPs induced greater distribution, without significantly changing diameter. The vitro...
When a metal deforms plastically, most of the mechanical energy expended in deformation process is converted into heat and remainder stored material. A method for calculation from an experimentally determined load-displacement curve elastic-plastic structure presented. The applied to problem simple tension polycrystalline technique uniaxial stress-strain
Recent years have witnessed intense interest in multifunctional surfaces that can be designed to switch between different functional states with various external stimuli including electric field, light, pH value, and mechanical strain. The present paper is aimed explore whether how a surface superhydrophobicity superhydrophilicity by an applied Based on well-established theories of structure buckling solid–liquid contact, we show this objective may achieved through hierarchically wrinkled...
It is reported that a flat free surface of stressed solid configurationally unstable under chemical etching and the roughness grows with different rates for spatial frequencies. The theory described in this Letter predicts shallow frequency below critical value while higher decays. was verified via an atomic force microscope experiment aluminum. This study provides simple experimental method to measure stress metals ceramics.
In this paper we explore the second transition in mechanism of frictional slip single–asperity contacts, which takes place at large contact sizes. This is a from single–dislocation–assisted (SDA) to multiple–dislocation–cooperated (MDC) slip. It found that friction stress controlled by dislocation nucleation for SDA slip, and mobility MDC A model concentric loops introduced analyse pile–up processes their relationship stress. Dislocations are stabilized be piled up as result non–zero...
General solutions of thermal stresses and material birefringence in polarization-maintaining optical fibers are presented. The give the at every point cross section various fibers. fundamental solution stress field is constructed by using complex variable method elasticity. When cores, inner claddings, or stress-inducing regions ellipses, circles, bow-tie shapes, exact closed-form can be found. average core center elliptical core, cladding, twin Panda, calculated compared. Among these...