A5033878265- Microfluidic and Capillary Electrophoresis Applications
- Nanopore and Nanochannel Transport Studies
- Microfluidic and Bio-sensing Technologies
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Electrohydrodynamics and Fluid Dynamics
- Force Microscopy Techniques and Applications
- High-Velocity Impact and Material Behavior
- Metal and Thin Film Mechanics
- Diamond and Carbon-based Materials Research
- Electrowetting and Microfluidic Technologies
- Microstructure and mechanical properties
- DNA and Nucleic Acid Chemistry
- Molecular Junctions and Nanostructures
- Modular Robots and Swarm Intelligence
- Advanced materials and composites
- Innovative Microfluidic and Catalytic Techniques Innovation
- Advanced Surface Polishing Techniques
- Electrostatics and Colloid Interactions
- Polymer Surface Interaction Studies
- Surface Treatment and Residual Stress
- Organizational Management and Innovation
- Satellite Communication Systems
- Antenna Design and Optimization
- Advanced biosensing and bioanalysis techniques
General Atomics (United States)
2013-2019
University of North Carolina at Chapel Hill
2009
Massachusetts Institute of Technology
2003-2006
Rockwell Automation (United States)
2005
University of Wisconsin–Madison
2004
Poly(dimethylsiloxane) is currently the material of choice for rapidly fabricating microfluidic devices. As size these devices decreases, a significant hydrodynamic flow generated due to permeation fluid through channel walls. We develop theoretical model verified by single bead tracking experiments, which demonstrates that large rates (>10 microm/s) can be passively in straight microchannel filled with water. Realizing this may unwanted some applications, we present method eliminate it...
The conformation and diffusion of a single DNA molecule confined between two parallel plates are examined using both experiments Brownian dynamics simulations accounting for hydrodynamic interactions. degree chain stretching the diffusivity characterized as function confinement channel geometry. Good agreement is found simulations, experiments, scaling theory predictions.
Molecular bottle-brushes are highly branched macromolecules with side chains densely grafted to a long polymer backbone. The brush-like architecture allows focusing of the side-chain tension backbone and its amplification from pico-Newton nano-Newton range. depends on overall molecular conformation surrounding environment. Here we study relation between brushes in solutions, melts, substrates. In find that dense attached every monomer is order f(0)N(3/8) athermal solvents, f(0)N(1/3) theta...
A basic tenet of material science is that the flow stress a metal increases as its grain size decreases, an effect described by Hall-Petch relation. This relation used extensively in design to optimize hardness, durability, survivability, and ductility structural metals. Letter reports experimental results new regime high pressures strain rates challenge this mechanical metallurgy. We report measurements plastic model body-centered-cubic tantalum made under conditions pressure (>100 GPa)...
The ability to controllably and continuously stretch large DNA molecules in a microfluidic format is important for gene mapping technologies such as Direct Linear Analysis (DLA). We have recently shown that electric field gradients can be readily generated device the resulting purely elongational. present single molecule fluorescence microscopy analysis of T4 (169 kbp) stretching hyperbolic contraction microchannel. In addition, we are able selectively pattern crosslinked gel anywhere inside...
We study the dynamics of single DNA molecules driven by an electric field into a stationary obstacle. These collisions are broadly classified as ``hook'' and ``roll-off'' events. show that obstacle-induced gradients stretch impacting thus greatly influence hooking probability. Consequently, in addition to collision geometry, determination probability depends on Deborah number (De) for $0.5<\mathrm{D}\mathrm{e}<40$. Individual impact highly configuration sensitive, characteristic polymers...
We present a kinematic analysis and experimental study of DNA deformation in electric field gradients. Specifically, we investigate near large insulating cylinder with single molecule fluorescence videomicroscopy. Because the electrophoretic velocity is potential field, shows that local any gradient pure elongation, quantified by strain rate orthogonal axes extension compression. From kinematics, construct Deborah number relating competing effects polymer elasticity. report highly...
Using single molecule fluorescence microscopy, we study the dynamics of an electric-field-driven DNA colliding with a stationary post. The radius obstacle is small compared to contour length molecules. Molecules that achieve hooked configurations which span were chosen for study. Four different types found: symmetric hairpins constant extension during unhooking, asymmetric increasing and rare multiply looped entangled configurations. important physics describing unhooking each classification...
Rippled metal foils are currently sought for high-strain-rate material strength studies at laser facilities. Because these metals typically cannot be diamond turned, we employ a microcoining process to imprint the [approximately]5-μm-deep by [approximately]50-μm-long ripples into surface. This work details recent developments fabricate rippled targets, specifically iron and tantalum. The consists of nitriding steel die, turning then pressing die polished foil choice. We show: advantages...
Driving a shock wave through the interface between two materials with different densities can result in Richtmyer-Meshkov or Rayleigh-Taylor instability and initial perturbations at will grow. If is sufficiently strong, lead to plastic flow interface. Material strength reduce amount of suppress growth. While such instabilities have been investigated 2D, no studies this phenomena performed 3D on strength.Initial seed hydrodynamic were coined into tantalum recovery targets. Two types used,...
The authors present an evaporative initiated chemical vapor deposition (iCVD) coater and use it to establish a submicron bonding process for millimeter‐scale foils with potentially rough surface features. uses simple benchtop design suited research labs, pre‐heated metal pins instead of hot filaments, direct evaporation reactants within the chamber. Coatings poly(glycidyl methacrylate) (pGMA) thickness 100–800 nm are achieved at rates 10–40 min −1 on substrates common in high energy laser...
High-strength droplet interfaces are attractive for many applications, specifically in cases where droplets channeled through fluidic devices and manipulated by electromagnetic fields. Using models experiments, we study the deformation of capsules with protein an electric field thin wide electrode gaps. Proteins chosen from candidates expected to display qualitatively different interfacial interactions strengths: a globular (bovine serum albumin), reversible cross-linking peptide (AFD4),...