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In this paper, we address the hydraulic flow of fluids on and within nanofabricated hydrophilic (as opposed to hydrophobic) surfaces, and the influence of an extended precursor film on the wetting dynamics of water penetrating a nano-textured array of posts that has no sealing surface (open-top). The width of the precursor film in front of the wetting edge delta is extraordinarily large, approximately 2 mm for our device, and it drives the wetting penetration film in the open- top array. We discuss the way this thin precursor film controls the movement of the macroscopic wetting front L-w and its dynamics in the nanofabricated array of posts. Rapid and controllable transport of nanoparticles in such an open top array of posts, as controlled by the precursor film, is demonstrated using a bump array textured morphology.

In this paper, we address the hydraulic flow of fluids on and within nanofabricated hydrophilic (as opposed to hydrophobic) surfaces, and the influence of an extended precursor film on the wetting dynamics of water penetrating a nano-textured array of posts that has no sealing surface (open-top). The width of the precursor film in front of the wetting edge delta is extraordinarily large, approximately 2 mm for our device, and it drives the wetting penetration film in the open- top array. We discuss the way this thin precursor film controls the movement of the macroscopic wetting front L-w and its dynamics in the nanofabricated array of posts. Rapid and controllable transport of nanoparticles in such an open top array of posts, as controlled by the precursor film, is demonstrated using a bump array textured morphology.

In this paper, we address the hydraulic flow of fluids on and within nanofabricated hydrophilic (as opposed to hydrophobic) surfaces, and the influence of an extended precursor film on the wetting dynamics of water penetrating a nano-textured array of posts that has no sealing surface (open-top). The width of the precursor film in front of the wetting edge delta is extraordinarily large, approximately 2 mm for our device, and it drives the wetting penetration film in the open- top array. We discuss the way this thin precursor film controls the movement of the macroscopic wetting front L-w and its dynamics in the nanofabricated array of posts. Rapid and controllable transport of nanoparticles in such an open top array of posts, as controlled by the precursor film, is demonstrated using a bump array textured morphology.

We show that it is possible to direct particles entrained in a fluid along trajectories much like rays of light in classical optics. A microstructured, asymmetric post array forms the core hydrodynamic element and is used as a building block to construct microfluidic metamaterials and to demonstrate refractive, focusing, and dispersive pathways for flowing beads and cells. The core element is based on the concept of deterministic lateral displacement where particles choose different paths through the asymmetric array based on their size: Particles larger than a critical size are displaced laterally at each row by a post and move along the asymmetric axis at an angle to the flow, while smaller particles move along streamline paths. We create compound elements with complex particle handling modes by tiling this core element using multiple transformation operations; we show that particle trajectories can be bent at an interface between two elements and that particles can be focused into hydrodynamic jets by using a single inlet port. Although particles propagate through these elements in a way that strongly resembles light rays propagating through optical elements, there are unique differences in the paths of our particles as compared with photons. The unusual aspects of these modular, microfluidic metamaterials form a rich design toolkit for mixing, separating, and analyzing cells and functional beads on-chip.

We present a versatile method for continuous-flow, on-chip biological processing of cells, large bio-particles, and functional beads. Using an asymmetric post array in pressure-driven microfluidic flow, we can move particles of interest across multiple, independent chemical streams, enabling sequential chemical operations. With this method, we demonstrate on-chip cell treatments such as labeling and washing, and bacterial lysis and chromosomal extraction. The washing capabilities of this method are particularly valuable because they allow many analytical or treatment procedures to be cascaded on a single device while still effectively isolating their reagents from cross-contamination. © The Royal Society of Chemistry.

We show that it is possible to direct particles entrained in a fluid along trajectories much like rays of light in classical optics. A microstructured, asymmetric post array forms the core hydrodynamic element and is used as a building block to construct microfluidic metamaterials and to demonstrate refractive, focusing, and dispersive pathways for flowing beads and cells. The core element is based on the concept of deterministic lateral displacement where particles choose different paths through the asymmetric array based on their size: Particles larger than a critical size are displaced laterally at each row by a post and move along the asymmetric axis at an angle to the flow, while smaller particles move along streamline paths. We create compound elements with complex particle handling modes by tiling this core element using multiple transformation operations; we show that particle trajectories can be bent at an interface between two elements and that particles can be focused into hydrodynamic jets by using a single inlet port. Although particles propagate through these elements in a way that strongly resembles light rays propagating through optical elements, there are unique differences in the paths of our particles as compared with photons. The unusual aspects of these modular, microfluidic metamaterials form a rich design toolkit for mixing, separating, and analyzing cells and functional beads on-chip.

We present a versatile method for continuous-flow, on-chip biological processing of cells, large bio-particles, and functional beads. Using an asymmetric post array in pressure-driven microfluidic flow, we can move particles of interest across multiple, independent chemical streams, enabling sequential chemical operations. With this method, we demonstrate on-chip cell treatments such as labeling and washing, and bacterial lysis and chromosomal extraction. The washing capabilities of this method are particularly valuable because they allow many analytical or treatment procedures to be cascaded on a single device while still effectively isolating their reagents from cross-contamination. © The Royal Society of Chemistry.

We present a versatile method for continuous-flow, on-chip biological processing of cells, large bio-particles, and functional beads. Using an asymmetric post array in pressure-driven microfluidic flow, we can move particles of interest across multiple, independent chemical streams, enabling sequential chemical operations. With this method, we demonstrate on-chip cell treatments such as labeling and washing, and bacterial lysis and chromosomal extraction. The washing capabilities of this method are particularly valuable because they allow many analytical or treatment procedures to be cascaded on a single device while still effectively isolating their reagents from cross-contamination. © The Royal Society of Chemistry.

We show that it is possible to direct particles entrained in a fluid along trajectories much like rays of light in classical optics. A microstructured, asymmetric post array forms the core hydrodynamic element and is used as a building block to construct microfluidic metamaterials and to demonstrate refractive, focusing, and dispersive pathways for flowing beads and cells. The core element is based on the concept of deterministic lateral displacement where particles choose different paths through the asymmetric array based on their size: Particles larger than a critical size are displaced laterally at each row by a post and move along the asymmetric axis at an angle to the flow, while smaller particles move along streamline paths. We create compound elements with complex particle handling modes by tiling this core element using multiple transformation operations; we show that particle trajectories can be bent at an interface between two elements and that particles can be focused into hydrodynamic jets by using a single inlet port. Although particles propagate through these elements in a way that strongly resembles light rays propagating through optical elements, there are unique differences in the paths of our particles as compared with photons. The unusual aspects of these modular, microfluidic metamaterials form a rich design toolkit for mixing, separating, and analyzing cells and functional beads on-chip.

The subject of the paper is the derivation and analysis of new multidimensional, high-resolution, finite volume evolution Galerkin (FVEG) schemes for systems of nonlinear hyperbolic conservation laws. Our approach couples a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of the multidimensional hyperbolic system, such that all of the infinitely many directions of wave propagation are taken into account. In particular, we propose a new FVEG-scheme, which is designed in such a way that for a linear wave equation system the approximate evolution operator calculates any one-dimensional planar wave exactly. This operator makes the FVEG-scheme stable up to a natural CFL limit of 1. Using the results obtained for the wave equation system a new approximate evolution operator for the linearised Euler equations is also derived. The integrals over the cell interfaces also need to be approximated with care; in this case our choice of Simpson's rule is guided by stability analysis of model problems. Second order resolution is obtained by means of a piecewise bilinear recovery. Numerical experiments confirm the accuracy and multidimensional behaviour of the new scheme.

The increasing demand for the transmission of widely disparate and complex communications signals over the base communication system will continue to place enormous loads upon the base cable plant as well as the operations and maintenance personnel involved. This report describes the various alternatives that may be applied to solve this growing problem. (Author)