Effect of the shear rate and residence time on the lysis of AC16 human cardiomyocyte cells via surface acoustic waves.

The efficient breakage of one cell or a concentration of cells for releasing intracellular material such as DNA, without damaging it, is the first step for several diagnostics or treatment processes. As the cell membrane is easy to bend but resistant to stretching, the exposure of the cell to a shear rate during a short period of time can be sufficient to damage the membrane and facilitate the extraction of DNA. However, how to induce high shear stresses on cells in small microliter volumes samples has remained an elusive problem.

In-droplet cell lysis of AC16 human cardiomyocyte cells surface acoustic waves.

Although several lysis methods are available, biomedical applications are pushing the demand for miniaturised systems and thus for new ways to lyse cells in small volumes. In this work, we demonstrate in-droplet cell lysis of AC16 human cardiomyocyte cells in 20 μL droplets using high frequency surface acoustic waves. The acoustic streaming leads to high shear flow creating porous or breaking the cell membrane and releasing intracellular material.

Improving superamphiphobicity by mimicking tree-branch topography.

when a droplet impacts on a superhydrophobic structured surface below a certain impact velocity, the droplet can bounce off completely from the surface. However, above such velocity a fraction of the droplet will pin on the surface. Surfaces capable of repelling water droplets are ubiquitous in nature or have been artificially fabricated.

Can Wicking Control Droplet Cooling?

Wicking, defined as absorption and passive spreading of liquid into a porous medium, has been identified as a key mechanism to enhance the heat transfer and prevent the thermal crisis. Reducing the evaporation time and increasing the Leidenfrost point (LFP) are important for an efficient and safe design of thermal management applications, such as electronics, nuclear, and aeronautics industry. Here, we report the effect of the wicking of superhydrophilic nanowires (NWs) on the droplet vaporization from low temperatures to temperatures above the Leidenfrost transition.

Analysis of dynamic surfactant mass transfer and its relationship to the transient stabilization of coalescing liquid-liquid dispersions.

In this work, experiments describing the behavior of the separation of a model liquid-liquid dispersion with various concentrations of a synthetic surfactant are presented which indicate that there is a dynamic stabilization of initially unstable emulsions that occurs when the initial surfactant concentration approaches the concentration that provides stable emulsions. A simple model is presented to suggest the mechanism for the dynamic stabilization of these emulsion systems that considers the redistribution of surfactant into the continuous phase after a coalescence event at the emulsion-bulk dispersed phase interface and the dynamic mass transport of surfactant in the continuous phase of the emulsion. The results indicate that coalescence at the interface between the emulsion layer and the bulk dispersed phase creates a local region in the vicinity of this interface where the concentration of the surfactant is much higher than the bulk surfactant concentration which could lead to a locally, dynamically stabilized emulsion at this interface.