Heat and mass transfer of evaporation by collisions between droplets and solid particles can be significantly different under different conditions and could be affected by many factors, such as, the diameter ratio of solid and droplet, the hydrodynamic characteristics of the droplet, temperature difference between solids and droplet, the geometry curvature, the bridge effect of two or three bal...

We demonstrate ElectroWetting-On-Dielectric (EWOD) transport and SQUID gradiometer detection of magnetic nanoparticles (MNPs) suspended in a 2 microl de-ionized water droplet. This proof-of-concept methodology constitutes the first development step towards a highly sensitive magnetic immunoassay platform with SQUID readout and droplet-based sample handling. Magnetic AC-susceptibility measuremen...

This paper reports the design and fabrication of a micromachined silicon pin that serves as a novel contact-printing tool. More specific application is in the DNA and protein microarray field for small and precise droplet printing onto a solid support. Our goal is to develop low cost, high performance silicon pins as simple replacement of the stainless-steel pins used in typical microarray robo...

The transient response of a millimeter-sized sessile droplet under electrical actuation is experimentally investigated. Under DC actuation, the droplet spreading rate increases as the applied voltage is increased due to the higher electrical forces induced. At sufficiently high DC voltages, competition between the electrical actuation force, droplet inertia, the retarding surface tension force ...

Using a comparative evaporation kinetics approach, we describe a new and accurate method for determining the equilibrium hygroscopic growth of aerosol droplets. The time-evolving size of an aqueous droplet, as it evaporates to a steady size and composition that is in equilibrium with the gas phase relative humidity, is used to determine the time-dependent mass flux of water, yielding informatio...

When a droplet hits a hot surface beyond the Leidenfrost temperature, the droplet will bounce on the hot surface. This unique bouncing phenomenon only occurs in the film boiling region. This paper discusses the relationship between the residence time of droplet and droplet bouncing phenomena during droplet impact on hot horizontal surfaces. In this experiment, aluminum (mirror polished) was sel...

Spray atomization is a common process found in different industries, where sprays under high injection pressure are widely recorded in the literature. Nonetheless, research on spray breakup mechanism under low pressure in pharmaceutical industry is still relatively rare. Numerical model in the Lagrangian approach was modified for simulating the spray formation from a nasal spray device in the c...

Understanding the evaporation of pesticide droplets and wetting of leaf surfaces can increase foliar application efficiency and reduce pesticide use. Evaporation time and wetted area of single pesticide droplets on hairy and waxy geranium leaf surfaces were measured under the controlled conditions for five droplet sizes and three relative humidity levels. Stereoscopic sequential images of the d...

The first droplet produced by a low-conductivity pendant/sessile subject to strong electric field is particularly important at the fundamental level because, in contrast steady electrospray phenomena, its ejection entails complex charge relaxation and electrokinetic processes. Besides, it technologically relevant because of very small diameter large per unit volume. In this work, we present an ...