Effect Of Molecular Structure On Liquid Slip,
2015
Selected Works
Effect Of Molecular Structure On Liquid Slip, Ajay Vadakkepatt, Yalin Dong, Seth Lichter, Ashlie Martini
Dr. Yalin Dong
Slip behavior of three liquids with distinct molecular shapes—linear (hexadecane), branched (pentaerythritol tetra), and a chain of rings (polyphenylether)—is studied using molecular dynamics simulation and reduced-order modeling. Slip at a liquid-solid interface is shown to be affected by the molecular structure of the liquid. A two-dimensional Frenkel-Kontorova model captures the fundamental structural features of the liquid molecules and gives insight into how molecules flex and slip along the surface. We formulate an approximation to the Peierls-Nabarro energy which incorporates both the position of liquid atoms relative to substrate atoms and molecular flexibility. We find that increased molecular flexibility can lead …
Physically Representative Atomistic Modeling Of Atomic-Scale Friction,
2015
The University of Akron, Main Campus
Physically Representative Atomistic Modeling Of Atomic-Scale Friction, Yalin Dong
Dr. Yalin Dong
Nanotribology is a research field to study friction, adhesion, wear and lubrication occurred between two sliding interfaces at nano scale. This study is motivated by the demanding need of miniaturization mechanical components in Micro Electro Mechanical Systems (MEMS), improvement of durability in magnetic storage system, and other industrial applications. Overcoming tribological failure and finding ways to control friction at small scale have become keys to commercialize MEMS with sliding components as well as to stimulate the technological innovation associated with the development of MEMS. In addition to the industrial applications, such research is also scientifically fascinating because it opens a …
Speed Dependence Of Atomic Stick-Slip Friction In Optimally Matched Experiments And Molecular Dynamics Simulations,
2015
University of Pennsylvania
Speed Dependence Of Atomic Stick-Slip Friction In Optimally Matched Experiments And Molecular Dynamics Simulations, Qunyang Li, Yalin Dong, Danny Perez, Ashlie Martini, Robert W. Carpick
Dr. Yalin Dong
The atomic stick-slip behavior of a Pt tip sliding on a Au(111) surface is studied with atomic force microscopy (AFM) experiments and accelerated (i.e., reduced sliding speed) molecular dynamics (MD) simulations. The MD and AFM conditions are controlled to match, as closely as possible, the geometry and orientation, load, temperature, and compliance. We observe clear stick-slip without any damage. Comparison of bothMDand AFM results with the thermally activated Prandtl-Tomlinson model shows that MD results at the highest speeds are not in the thermally activated regime. At lower speeds, within the thermally activated regime, AFM and MD provide consistent energetics, but …
Atomistic Study Of Lateral Contact Stiffness In Friction Force Microscopy,
2015
The University of Akron, Main Campus
Atomistic Study Of Lateral Contact Stiffness In Friction Force Microscopy, Huang Gao, Yalin Dong, Ashlie Martini
Dr. Yalin Dong
The effective stiffness of a friction force microscope tip–substrate system is an important parameter that describes the relationship between lateral force and elastic deformation. In this study, we use a multi-spring model to simplify the system, where two contributions, the tip apex stiffness and the lateral contact stiffness, are discussed in detail. Molecular dynamics simulations are used to characterize stiffness by simulating a tip apex subject to shear or sliding over a substrate surface. The results show that, although the height of the tip apex and tip–substrate orientation affect the various stiffness contributions, the contact itself dominates the overall compliance.
A Thermal Management Device For A Lower-Limb Prosthesis,
2015
University of Akron Main Campus
A Thermal Management Device For A Lower-Limb Prosthesis, Yu Han, Fan Liu, Garrett Dowd, Jiang Zhe
Dr. Jiang Zhe
Excessive heat and the resulted perspiration within a prosthetic socket were the most common causes for reporting a reduced quality of life for prosthesis users. This paper presents a novel thermal management device to maintain a constant skin temperature for a lower-limb prosthesis. To decrease the prosthetic socket's thermal resistance, heat pipes were used to concentrate heat flux from the simulated skin surface to a cooling region on the outer surface of the socket where a compact heat sink was attached. A small fan was used to convect heat from the heat sink to the ambient surroundings. Thermal resistance of …
Effects Of Sea Surface Temperature, Cloud Radiative And Microphysical Processes, And Diurnal Variations On Rainfall In Equilibrium Cloud-Resolving Model Simulations,
2015
University of Akron, main campus
Effects Of Sea Surface Temperature, Cloud Radiative And Microphysical Processes, And Diurnal Variations On Rainfall In Equilibrium Cloud-Resolving Model Simulations, Jiang Zhe, Li Fan, Zhou Shu, Gao Ting
Dr. Jiang Zhe
No abstract provided.
Thermal And Fluid Field Simulation Of Single Pulse Discharge In Dry Edm,
2015
University of Akron, main campus
Thermal And Fluid Field Simulation Of Single Pulse Discharge In Dry Edm, T. Wang, Jiang Zhe, Y. Zhang, Y. Li, X. Wen
Dr. Jiang Zhe
Dry Wire Electrical Discharge Machining (WEDM) is a newly developed technology that uses gases as dielectric and is in favor of environmental protection. Dry finishing of WEDM offers advantages such as better straightness, lower surface roughness and shorter gap length. Experimental studies show that the machining behaviors in dry conditions are quite different from those in conventional liquid dielectric. In order to explore the processing mechanism of dry WEDM, this paper studies the single pulse discharge mechanism in gas with finite element method. In order to obtain the crater morphology with edge raised, the fluid field was simulated by ANAYS …
High Throughput Microfluidic Electrical Impedance Flow Cytometry For Assay Of Micro Particles,
2015
University of Akron Main Campus
High Throughput Microfluidic Electrical Impedance Flow Cytometry For Assay Of Micro Particles, Ashish Jagtiani, Jiang Zhe
Dr. Jiang Zhe
No abstract provided.
Optimal Design And Simulation Of A Cross-Plane Micro-Thermoelectric Generator,
2015
University of Akron, main campus
Optimal Design And Simulation Of A Cross-Plane Micro-Thermoelectric Generator, Xiao Zhu, De Li, Ben Liu, Jiang Zhe
Dr. Jiang Zhe
No abstract provided.
Effects Of Particle's Off-Axis Position, Shape, Orientation And Entry Position On Resistance Changes Of Micro Coulter Counting Devices,
2015
University of Akron Main Campus
Effects Of Particle's Off-Axis Position, Shape, Orientation And Entry Position On Resistance Changes Of Micro Coulter Counting Devices, Zhenpeng Qin, Jiang Zhe, Guo-Xiang Wang
Dr. Jiang Zhe
With the recent advance in micro/nano-fabrication technology, micro Coulter counters have been widely used in detecting and characterizing micro- and nanoscale objects. In this paper, the electrical resistance change during translocation of a non-conducting particle through a channel is studied numerically. The numerical results are validated by proven analytical results available in the literature. The effects of particle's off-axis position, shape and orientation, and entry position are studied for particles with a large dynamic range. From the numerical results, a new fitted correlation is proposed that can accurately predict the resistance change caused by off-axis spherical particles regardless of their …
High-Throughput, Single-Stream Microparticle Focusing Using A Microchannel With Asymmetric Sharp Corners,
2015
University of Arkon, main campus
High-Throughput, Single-Stream Microparticle Focusing Using A Microchannel With Asymmetric Sharp Corners, Liang-Liang Fan, Yu Han, Xu-Kun He, Liang Zhao, Jiang Zhe
Dr. Jiang Zhe
A new microfluidic device for fast and high-throughput particle focusing is reported. The particle focusing is based on the combination of inertial lift force effect and centrifugal force effect generated in a microchannel with a series of repeated asymmetric sharp corners on one side of the channel wall. The inertial lift force induces two focused particle streams in the microchannel, and the centrifugal force generated at the sharp corner structures tends to drive the particles laterally away from the corner. With the use of a series of repeated asymmetric sharp corner structures, a single and highly focused particle stream was …
Continuous 3d Particle Focusing In A Microchannel With Curved And Symmetric Sharp Corner Structures,
2015
University of Akron, main campus
Continuous 3d Particle Focusing In A Microchannel With Curved And Symmetric Sharp Corner Structures, Liang-Liang Fan, Xu-Kun He, Yu Han, Jiang Zhe, Liang Zhao
Dr. Jiang Zhe
No abstract provided.
Sheathless Size-Based Acoustic Particle Separation,
2015
University of Akron, main campus
Sheathless Size-Based Acoustic Particle Separation, Rasim Guldiken, Myeong Jo, Nathan Gallant, Utkan Demirci, Jiang Zhe
Dr. Jiang Zhe
Particle separation is of great interest in many biological and biomedical applications. Flow-based methods have been used to sort particles and cells. However, the main challenge with flow based particle separation systems is the need for a sheath flow for successful operation. Existence of the sheath liquid dilutes the analyte, necessitates precise flow control between sample and sheath flow, requires a complicated design to create sheath flow and separation efficiency depends on the sheath liquid composition. In this paper, we present a microfluidic platform for sheathless particle separation using standing surface acoustic waves. In this platform, particles are first lined …
A Versatile Microparticle-Based Immunoaggregation Assay For Macromolecular Biomarker Detection And Quantification,
2015
University of Akron Main Campus
A Versatile Microparticle-Based Immunoaggregation Assay For Macromolecular Biomarker Detection And Quantification, Haiyan Wu, Yu Han, George G. Chase, Qiong Tang, Chen-Jung Lee, Bin Cao, Jiang Zhe, Gang Cheng
Dr. Jiang Zhe
The rapid, sensitive and low-cost detection of macromolecular biomarkers is critical in clinical diagnostics, environmental monitoring, research, etc. Conventional assay methods usually require bulky, expensive and designated instruments and relative long assay time. For hospitals and laboratories that lack immediate access to analytical instruments, fast and low-cost assay methods for the detection of macromolecular biomarkers are urgently needed. In this work, we developed a versatile microparticle (MP)-based immunoaggregation method for the detection and quantification of macromolecular biomarkers. Antibodies (Abs) were firstly conjugated to MP through streptavidin-biotin interaction; the addition of macromolecular biomarkers caused the aggregation of Ab-MPs, which were subsequently …
Numerical Analysis Of Rapid Micromixers Utilizing Magnetic Particles,
2015
University of Akron Main Campus
Numerical Analysis Of Rapid Micromixers Utilizing Magnetic Particles, Yiou Wang, Jiang Zhe, Benjamin Chung, Prashanta Dutta
Dr. Jiang Zhe
No abstract provided.
Zwitteration Of Dextran: A Facile Route To Integrate Antifouling, Switchability And Optical Transparency Into Natural Polymers,
2015
University of Akron Main Campus
Zwitteration Of Dextran: A Facile Route To Integrate Antifouling, Switchability And Optical Transparency Into Natural Polymers, Bin Cao, Linlin Li, Haiyan Wu, Qiong Tang, Bingbing Sun, He Dong, Jiang Zhe, Gang Cheng
Dr. Jiang Zhe
This communication reports a facile method for zwitteration of dextran with carboxybetaine (CB), which integrates superior antifouling properties, switchability between zwitterionic and cationic forms, as well as enhanced optical transparency into one polysaccharide material. This study provides a new avenue for generating multifunctional zwitterionic CB materials in situ.
A High Sensitivity Inductive Sensor For Blade Tip Clearance Measurement,
2015
University of Akron, main campus
A High Sensitivity Inductive Sensor For Blade Tip Clearance Measurement, Li Du, Xiaoliang Zhu, Jiang Zhe
Dr. Jiang Zhe
A multiplexed inductive sensor consisting of multiple mini-sized planar spiral coils for detecting multiple tip clearances of rotor blades is presented. The sensor measures the tip clearances by monitoring the inductance changes of planar spiral coils caused by the passage of the rotor blades. A resonance frequency division multiplexing technique and parallel LC resonance measurement were applied to the multiple sensor coils, making it feasible to measure multiple tip clearances using only one set of measurement electronics with high sensitivity and resolution. The results from tests conducted on a bench-top test rig have demonstrated that the sensor is capable of …
Label-Free Biomarker Assay In A Microresistive Pulse Sensor Via Immunoaggregation,
2015
University of Akron, main campus
Label-Free Biomarker Assay In A Microresistive Pulse Sensor Via Immunoaggregation, Yu Han, Haiyan Wu, Fan Li, Gang Cheng, Jiang Zhe
Dr. Jiang Zhe
We present a label-free biomarker detection method based on immunoaggregation and resistive pulse sensing technology. In this approach, target biomarkers and antibody (Ab)-functionalized microparticles are mixed to form biomarker–microparticle aggregates. A resistive pulse sensor is then used to measure the sizes and count the number of aggregates. The measured volume fraction of the aggregates represents the concentration of the targeted biomarker. In our tests, human ferritin, used as a biomarker, triggered the aggregation of antiferritin Ab-functionalized microparticles in phosphate-buffered saline (PBS). The volume fraction of aggregates increased with the increased ferritin concentration. We also demonstrated the detection of human ferritin …
Continuous Size-Based Separation Of Microparticles In A Microchannel With Symmetric Sharp Corner Structures,
2015
The University of Akron, Main Campus
Continuous Size-Based Separation Of Microparticles In A Microchannel With Symmetric Sharp Corner Structures, Liang-Liang Fan, Xu-Kun He, Yu Hun, Li Du, Liang Zhao, Jiang Zhe
Dr. Jiang Zhe
A new microchannel with a series of symmetric sharp corner structures is reported for passive size-dependent particle separation. Micro particles of different sizes can be completely separated based on the combination of the inertial lift force and the centrifugal force induced by the sharp corner structures in the microchannel. At appropriate flow rate and Reynolds number, the centrifugal force effect on large particles, induced by the sharp corner structures, is stronger than that on small particles; hence after passing a series of symmetric sharp corner structures, large particles are focused to the center of the microchannel, while small particles are …
An Integrated Lubricant Oil Conditioning Sensor Using Signal Multiplexing,
2015
University of Akron, Main Campus
An Integrated Lubricant Oil Conditioning Sensor Using Signal Multiplexing, Zhu Xiaoliang, Li Du, Jiang Zhe
Dr. Jiang Zhe
One effective approach to detect signs of potential failure of a rotating or reciprocating machine is to examine the conditions of its lubrication oil. Here we present an integrated oil condition sensor for detecting both wear debris and lubricant properties. The integrated sensor consists of miniature multiplexed sensing elements for detection of wear debris and measurements of viscosity and moisture. The oil debris sensing element consists of eight sensing channels to detect wear debris in parallel; the elements for measuring oil viscosity and moisture, based on interdigital electrode sensing, were fabricated using micromachining. The integrated sensor was installed and tested …
