We used the lattice Boltzmann method to study the displacement of a two-dimensional immiscible droplet subject to gravitational forces in a channel. The dynamic behavior of the droplet is shown, and the effects of the contact angle, Bond number ~the ratio of gravitational to surface forces!, droplet size, and density and viscosity ratios of the droplet to the displacing fluid are investigated. ...

We present an experimental investigation of the effect of kinetic energy on the ion doping efficiency of superfluid helium droplets using cesium cations from a thermionic emission source. The kinetic energy of Cs(+) is controlled by the bias voltage of a collection grid collinearly arranged with the droplet beam. Efficient doping from ions with kinetic energies from 20 eV up to 480 V has been o...

In hybrid laser–MIG keyhole welding, anti-crack elements can be added into the weld pool through a filler metal in anticipation of compensating mass loss, preventing porosity formation and improving compositional and mechanical properties of the welds. Understanding the mixing and diffusion of the filler metal in the molten pool is vital to achieve these desired objectives. In this study, mathe...

We have developed a gene transfection method called water-in-oil droplet electroporation (EP) that uses a dielectric oil and a liquid droplet containing live cells and exogenous DNA. When a cell suspension droplet is placed between a pair of electrodes, an intense DC electric field can induce droplet deformation, resulting in an instantaneous short circuit caused by the droplet elongating and c...

Generating chemical libraries in droplet form is vital to the adoption of microdroplet systems in high-throughput screening (HTS). This paper presents microfractionation in droplets (μFD), a method for generating heterogeneous droplet libraries using standard separation processes. In μFD, compounds eluting from a separation column are permanently encapsulated into droplets by a droplet generato...

We study dense and highly polydisperse emulsions at droplet volume fractions ϕ≥0.65. We apply oscillatory shear and observe droplet motion using confocal microscopy. The presence of droplets with sizes several times the mean size dramatically changes the motion of smaller droplets. Both affine and nonaffine droplet motions are observed, with the more nonaffine motion exhibited by the smaller dr...

We developed a lattice Boltzmann model to investigate the droplet dynamics in microfluidic devices. In our model, a stress-free boundary condition was proposed to conserve the total mass of flow system and improve the numerical stability for flows with low Reynolds number. The model was extensively validated by the benchmark cases including the Laplace’s law, the static contact angles at solid ...

A droplet-based bioreaction microsystem has been developed with automated droplet generation and confinement. On-chip electronic sensing is employed to track the position of the droplets by sensing the oil/aqueous interface in real time. The sensing signal is also used to control the pneumatic supply for moving as well as automatically generating four different nanolitre-sized droplets. The act...

We report characterization of spray-based nanoporous particle synthesis for use in the cathode of lithiumion batteries. Ultrasonic Microarray Spray Tuning (uMIST) was used to create microdroplets of salt solutions and battery material precursors, and the size distributions of produced microdroplets were investigated with a MicroOrifice Uniform Deposit Impactor (MOUDI). Experimental challenges a...

...................................................................................................................... 3 List of publications and manuscript ......................................................................... 9 Contributions to the publications ........................................................................... 10 Table of contents ....................................