Double emulsion production in glass capillary microfluidic device: Parametric investigation of droplet generation behaviour

Microfluidic devices are promising tools for the production of monodispersed tuneable complex emulsions. This review highlights the advantages of microfluidics for the fabrication of emulsions and presents an overview of the microfluidic emulsification methods including two-step and single-step methods for the fabrication of high-order multiple emulsions (double, triple, quadruple and quintuple) and emulsions with multiple and/or multi-distinct inner cores. The microfluidic methods for the formation of multiple emulsion drops with ultra-thin middle phase, multi-compartment jets, and Janus and ternary drops composed of two or three distinct surface regions are also presented. Different configurations of microfluidic drop makers are covered, such as co-flow, T-junctions and flow focusing (both planar and three-dimensional (3D)). Furthermore, surface modifications of microfluidic channels and different modes of droplet generation are summarized. Non-confined microfluidic geometries used for buoyancy-driven drop generation and membrane integrated microfluidics are also discussed. The review includes parallelization and drop splitting strategies for scaling up microfluidic emulsification. The productivity of a single drop maker is typically 1 L/h, which requires combining drop makers into twodimensional (2D) and 3D assemblies fed from a single set of inlet ports through a network of distribution and collection channels.

Microfluidic Production of Multiple Emulsions

Building functional materials for health care and pharmacy from microfluidic principles and Flow Focusing.

Ink jet technology for computer controlled printing has been under development for 25 years or so. A number of technological approaches have been developed, several of these approaches resulting in commercial products with an impressive range of capabilities. This paper is a brief summary of ink jet printing, emphasizing technological approaches of contemporary technical and commercial importance.

Ink Jet Printing

This paper aims to present a first step toward developing a comprehensive methodology for fully resolved numerical simulations of fusion deposition modeling (FDM).,A front-tracking/finite volume method previously developed for simulations of multiphase flows is extended to model the injection of hot polymer and its cooling down.,The accuracy and convergence properties of the new method are tested by grid refinement, and the method is shown to produce convergent solutions for the shape of the filament, the temperature distribution, contact area and reheat region when new filaments are deposited on top of previously laid down filaments.,The present paper focuses on modeling the fluid flow and the cooling. The modeling of solidification, volume changes and residual stresses will be described in Part II.,The ability to carry out fully resolved numerical simulations of the fusion deposition process is expected to help explore new deposition strategies and provide the “ground truth” for the development of reduced-order models.,The present paper is the first fully resolved simulation of the deposition in fusion filament modeling.

Fully resolved numerical simulations of fused deposition modeling. Part I: fluid flow

Numerical investigations of drop solidification on a cold plate in the presence of volume change

Computations of breakup modes in laminar compound liquid jets in a coflowing fluid

We use a front-tracking method to simulate solidi cation with volume change of a droplet on a xed cooling plate. The problem includes temporal evolution of three interfaces, i.e., solid–liquid, solid–air, and liquid–air, that are explicitly tracked under the assumption of axisymmetry. The solid–liquid interface is propagated with a normal velocity that is calculated from the normal temperature gradient across the front and the latent heat. The liquid–air front is advected by the velocity interpolated from nearest bulk uid ow velocities. Accordingly, the evolution of the solid–air front is simply the temporal imprint of the triple point at which simple and straightforward conditions are imposed. The governing Navier–Stokes equations are solved for the whole domain, setting the velocities in the solid phase to zero and with the non-slip condition on the solid–liquid interface. Computational results are compared with exact solutions for twodimensional Stefan problems and with corresponding experimental results, and show good agreement.

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A Front-Tracking Method for Three-Phase Computations of Solidification with Volume Change

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Truong V. Vu

Papers

Numerical investigations of drop solidification on a cold plate in the presence of volume change

Computations of breakup modes in laminar compound liquid jets in a coflowing fluid

A Front-Tracking Method for Three-Phase Computations of Solidification with Volume Change

Production of Hollow Spheres of Eutectic Tin-Lead Solder through a Coaxial Nozzle

Numerical simulations of solidification around two tandemly-arranged circular cylinders under forced convection