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We actuate with light & magnets, we fold & unfold DNA, we cell-free express proteins, we play with drops, marbles & interfaces, we organize particles, we harness coffee rings.

Optical drop generation, fusion and mixing!


07 July 2015. Our paper "High-throughput photocontrol of water drop generation, fusion, and mixing in a dual flow-focusing microfluidic device" has just been accepted for publication in Comptes Rendus Chimie (Elsevier journal published by the French Academy of Science)


We describe the first method to control, in a single microfluidic device, the generation, fusion, and mixing of pico- to nanoliter water-in-oil drops using a straightforward LED light stimulus. This is achieved by implementing a photosensitive surfactant in the water phases of a novel dual flow-focusing microfluidic configuration. UV illumination at 365 nm enables dynamic switch of the flow behaviour between a stable dual jet regime (-UV) and a stable dual drop regime (+UV), thus allowing us to generate on-demand two distinct populations of water drops. These drops are fused and mixed downstream inside expansion chambers, offering both a dynamic control by light stimulation and a controllable degree of fusion and mixing by the positions of chambers. The mixing inside the fused drops is found to be much faster than diffusion due to the chaotic advection inside the moving drops.

Reference:

High-throughput photocontrol of water drop generation, fusion, and mixing in a dual flow-focusing microfluidic device
L. Nurdin, A. Venancio-Marques, S. Rudiuk, M. Morel, D. Baigl*
CR Chimie 2015, in press