Motion of a droplet on a planar surface has applications in droplet-based lab on a chip technology. This paper reports the experimental results of the shape, contact angles, and motion of ferrofluid droplets driven by a permanent magnet on a planar homogeneous surface. The water-based ferrofluid in use is a colloidal suspension of single-domain magnetic nanoparticles. The effect of the magnetic...

Microfluidics has been used to perform various chemical operations for pL–nL volumes of samples, such as mixing, reaction and separation, by exploiting diffusion, viscous forces, and surface tension, which are dominant in spaces with dimensions on the micrometer scale. To further develop this field, we previously developed a novel microfluidic device, termed a microdroplet collider, which explo...

A novel discrete element spray granulation model capturing the key features of fluidised bed hydrodynamics, liquid-solid contacting and agglomeration is presented. The model computes the motion of every individual particle and droplet in the system, considering the gas phase as a continuum. Micro scale processes such as particle-particle collisions, droplet-particle coalescence and agglomeratio...

We use a three-dimensional lattice Boltzmann model to investigate the spreading of mesoscale droplets on homogeneous and heterogeneous surfaces. On a homogeneous substrate the base radius of the droplet grows with time as t for a range of viscosities and surface tensions. The time evolutions collapse onto a single curve as a function of a dimensionless time. On a surface comprising of alternate...

Ice accumulation hinders the performance of, and poses safety threats for, infrastructure both on the ground and in the air. Previously, rationally designed superhydrophobic surfaces have demonstrated some potential as a passive means to mitigate ice accretion; however, further studies on material solutions that reduce impalement and the contact time for impacting supercooled droplets (high vis...

Two basic methods have been used to relate the change in droplet number concentration to aerosol number concentration. The first method uses empirically derived relationships based on either observed aerosol number concentrations and droplet concentrations or observed aerosol sulfate or droplet mass concentrations and droplet number concentrations. This method was followed by Jones et al. (1994...

Abstract Accurately prediction of dispersion and polydispersity droplet flow is not a trivial task due to the complex behavior size distribution (DSD) strong state instantaneous velocity on shape droplet. Describing sizes velocities droplets initially formed in sprays an essential piece information needed spray modeling, which used define initial downstream two-phase fields’ predictive computat...

Despite the recent interest in droplet-based microfluidics using electrowetting-on-dielectric (EWOD), fundamental understanding of the fluid dynamics remains limited to two-dimensional (2D) reduction of the Navier-Stokes equation. Experimental data are in dire need to verify the predictions and advance the field. We report an investigation of the flow inside droplets actuated by EWOD in air usi...

Biofabrication commonly involves the use of liquid droplets to transport cells to the printed structure. However, the viability of the cells after impact is poorly controlled and understood, hampering applications including cell spraying, inkjet bioprinting, and laser-assisted cell transfer. Here, we present an analytical model describing the cell viability after impact as a function of the cel...