In many electrowetting on dielectric (EWOD) based microfluidics devices, droplet actuation speed is a crucial performance-controlling parameter. Our present study aims to characterize and study droplet speed in a typical EWOD device. First, a practical droplet speed measurement method has been methodically demonstrated and some related velocity terms have been introduced. Next, influence of ele...

BACKGROUND Pandoraea spp. are recently discovered bacteria, mainly recovered from cystic fibrosis (CF) patients, but their epidemiology and clinical significance are not well known. We describe an epidemic spread of Pandoraea pulmonicola from 2009 in our CF center, involving 6 out of 243 CF patients. METHODS Bacterial identification used amplified ribosomal DNA restriction analysis (ARDRA), M...

We present a droplet microfluidic method to extract molecules of interest from a droplet in a rapid and continuous fashion. We accomplish this by first marginalizing functionalized super-paramagnetic beads within the droplet using a magnetic field, and then splitting the droplet into one droplet containing the majority of magnetic beads and one droplet containing the minority fraction. We quant...

BACKGROUND Aerosols and droplets are produced during many dental procedures. With the advent of the droplet-spread disease severe acute respiratory syndrome, or SARS, a review of the infection control procedures for aerosols is warranted. TYPES OF STUDIES REVIEWED The authors reviewed representative medical and dental literature for studies and reports that documented the spread of disease th...

While Binder Jet Additive Manufacturing (BJAM) has great potential, its implementation is limited by defects in the finished parts. An improved understanding of how printing parameters impact quality printed parts needed. Prior work on droplet/powder interactions BJAM focused individual lines, this shows that successful layer formation favors larger droplet spacing than viable lines. When layer...

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. ...

Here we show that dielectrophoretic (DEP) liquid actuation can be used to dispense arrays of nanoliter-sized droplets loaded with biomolecules. Size-based enrichment of these biomolecules occurs rapidly and simultaneously with the droplet dispensing. The physical mechanism responsible for the effect is the positive DEP force directed toward the electrodes that is imposed by the non-uniform elec...

−Stable hydrocarbon oil (hexadecane, C16)/nonionic surfactant (HCO-60, Span 80)/water system oil-inwater nanoemulsions were prepared by the phase inversion composition method at elevated temperature. To minimize droplet size, the composition ratio for stable nanoemulsions, we experimented by changing the HLB value, oil/surfactant ratio, and droplet volume fraction. When the HLBmix value 11, the...

The droplet size can influence the application of a spray system. We apply grey theory in establishing a model of forecasting droplet size. The example used in this study shows that this method is precise in forecasting the droplet size, and is helpful to choose the other parameters of a spray system within a certain droplet size.

Achieving the increasingly fast mixing requirements posed by the chemical, biological, and life science community for confined microchannel droplet flows remains an engineering challenge. The viscous and surface tension forces that often dominate microflows undermine fast, efficient mixing. A novel mixing arrangement based on droplet collisions has been developed that significantly improves mix...