Superhydrophobic surfaces often incorporate roughness on both micron and nanometer length scales, although a satisfactory understanding of the role this hierarchical in causing superhydrophobicity remains elusive. We present two-dimensional thermodynamic model to describe wetting hierarchically grooved by droplets for which influence gravity is negligible. By creating phase diagrams with single-scale roughness, we find that leads greatly expanded superhydrophobic domains space over those...

Abstract We report an autonomous oscillatory micromotor system in which active colloidal particles form clusters, the size of changes periodically. The consists aqueous suspension silver orthophosphate microparticles under UV illumination, presence varying concentrations hydrogen peroxide. colloid first attract each other to clusters. After a short delay, these clusters abruptly disperse and oscillation begins, alternating between clustering dispersion particles. cluster initiates, wave...

We present computational results for the transport and absorption of ozone in right middle lobe a rhesus monkey lung using both an anatomically correct airway structure axisymmetric single-path model. The accurate geometry is created from magnetic resonance images lung. equations governing flow concentration distribution are solved numerically quasi-steady under quiet breathing conditions pseudo-first-order kinetics reaction with antioxidants lining fluid. rate each generation along selected...

This paper describes microencapsulation of antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, Carmustine) into biodegradable polymer poly(lactic-co-glycolic) acid (PLGA) using an electrojetting technique. The resulting BCNU-loaded PLGA microcapsules have significantly higher drug encapsulation efficiency, more tunable loading capacity, and (3) narrower size distribution than those generated other methods.

We present the results of numerical simulations three-dimensional thermocapillary motion deformable viscous drops under influence a constant temperature gradient within second liquid medium. In particular, we examine effects shape deformations and convective transport momentum energy on migration velocity drop. A method based continuum model for fluid–fluid interface is used to account finite drop deformations. An oct-tree adaptive grid refinement scheme integrated into in order track...

Hydrogenated amorphous silicon (a-Si:H) is one of the most technologically important semiconductors. The challenge in producing it from SiH4 precursor to overcome a significant kinetic barrier decomposition at low enough temperature allow for hydrogen incorporation into deposited film. use high concentrations possible means increase reaction rates temperatures, but conventional reactors such an approach produces large numbers homogeneously nucleated particles gas phase, rather than desired...

We present a theoretical model for predicting equilibrium wetting configurations of two-dimensional droplets on periodically grooved hydrophobic surfaces. The main advantage our is that it accounts pinning/depinning the contact line at step edges, feature not captured by Cassie and Wenzel models. also account effects gravity (via Bond number) various can occur. Using free-energy minimization, we construct phase diagrams depicting dependence modes (including number surface grooves involved in...

We used molecular dynamics (MD) simulations to study the wetting of Lennard-Jones cylindrical droplets on surfaces patterned with grooves. By scaling surface topography parameters droplet size, we find that preferred modes and contact angles become independent size. This result is in agreement a mathematical model for free energy at small Bond numbers which effects gravity are negligible. The MD various good those predicted by model. construct phase diagrams dependence observed surface....

The Wenzel model, commonly used for predicting the equilibrium contact angle (CA) of drops which penetrate asperities a rough surface, does not account liquid volume stored in asperities. Interestingly, many previous experimental and molecular dynamics studies have noted discrepancies between observed CAs those predicted by model because this neglected volume. Here, we apply thermodynamic to wetting periodically patterned surfaces derive volume-corrected equation limit small pattern...

Abstract Granular hydrogel scaffolds (GHS) are fabricated via placing microparticles (HMP) in close contact (packing), followed by physical and/or chemical interparticle bond formation. Gelatin methacryloyl (GelMA) GHS have recently emerged as a promising platform for biomedical applications; however, little is known about how the packing of building blocks, physically crosslinked soft GelMA HMP, affects (pore microarchitecture and mechanical/rheological properties) biological (in vitro...

The effect of surfactants on the motion and deformation liquid drops in Poiseuille flow through circular tubes at low Reynolds numbers is examined. Assuming no bulk transport surfactant, boundary integral method used conjunction with a convective–diffusion equation to determine distribution surfactant deformed surface drop. velocity shape drop as well extra pressure loss due presence are calculated. Increasing Péclet number found produce large variations concentration across resulting...

Locomotion of microorganisms plays a vital role in most their biological processes. In many these processes, are exposed to complex fluids while swimming confined domains, such as spermatozoa mucus mammalian reproduction tracts or bacteria extracellular polymeric matrices during biofilm formation. Thus, it is important understand the kinematics propulsion viscoelastic fluid near no-slip boundary. We use squirmer model with time-reversible body motion analytically investigate an Oldroyd-B...

Abstract An ideal neural device enables long‐term, sensitive, and selective communication with the nervous system. To accomplish this task, material interface should mimic biophysical biochemical properties of tissue. By contrast, microfabricated probes utilize hard metallic conductors, which hinder their long‐term performance because these materials are not intrinsically similar to soft This study reports a method for fabrication monodisperse conducting polymer microcups. It is demonstrated...

We present a flux-based analysis of the motion spherical electrocatalytic nanomotors based on an electrokinetic model with general distribution cation flux over motor surface. Using method matched asymptotic expansions, we find expression for velocity to leading order in Debye length limit weak surface flux. The nanomotor is proportional first Legendre coefficient and depends non-linearly interfacial potential at particle surface, inversely fluid viscosity background ion concentration...

Neither a purely deterministic rotary nanomotor nor orientational diffuser exhibits long-term translational motion, but coupling rotation to diffusion yields diffusion. We demonstrate that this effective can easily dominate the ordinary thermal for experimentally relevant nanomotors, and is chiral. Unpowered chiral particles do not exhibit diffusion, nanorotor has both handedness an instantaneous direction of powered thus---unlike unpowered particle---its diffusional motion distinguish left...

Using the method of matched asymptotic expansions, we derive a general expression for speed prolate spheroidal electrocatalytic nanomotor in terms interfacial potential and physical properties motor environment limit small Debye length Péclet number. This greatly increases range geometries that can be handled without resorting to numerical simulations, since wide shapes from spherical needle-like, particular common cylindrical shape, well-approximated by spheroids. For piecewise-uniform...

Photothermal atomic force microscopy coupled with infrared spectroscopy (AFM-IR) brings significant value as a spatially resolved surface analysis technique for disordered oxide materials such glasses, but additional development and fundamental understanding of governing principles is needed to interpret AFM-IR spectra, since the existing theory described organic does not work high extinction coefficients (IR) absorption. This paper describes theoretical calculation transient temperature...

The dynamic interplay between the composition of lipid membranes and behavior membrane-bound enzymes is critical to understanding cellular function viability, design membrane-based biosensing platforms. While there a significant body knowledge about how dynamics affect enzymes, little known enzyme catalysis influences motility lateral transport on membranes. Using enzyme-attached lipids in supported bilayers (SLBs), we provide direct evidence catalysis-induced fluid flow that underlies...

The steady pressure-driven flow of an incompressible Newtonian fluid through axisymmetric capillary whose diameter varies sinusoidally in the axial direction is studied numerically under conditions negligible inertial effects. boundary integral formulation used to obtain detailed velocity and pressure distributions within capillary, determine effects amplitude wavelength corrugation on kinematic structure flow. In particular, critical values geometric parameters leading reversal expansion...