Microfluidics

The microfluidic platform is dedicated to studying the behavior of complex fluids.

The microfluidic platform is dedicated to studying the behavior of complex fluids, with four main objectives:

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Objective 1: fluid performance for thermal management of electrical systems

To this end, this platform analyzes the evaporation of drops of nanofluids, oils and emulsions, dielectric fluids and binary fluids under thermal stress. Experiments measure surface tensions, contact angles and evaporation rates on smooth or textured heated substrates. It enables surface wettability to be optimized for optimal cooling.

Morphologies de dépôts des nanoparticules de CuO sur des substrats en silicium à plusieurs températures

Evolution des coefficients de transfert thermique lors de l’ébullition dans un microcanal

Objective 2: analysis of microchannel boiling

A test loop tracks the boiling of refrigerants and heat transfer fluids in microchannel heat exchangers. High-level instrumentation enables visualization in the visible and infrared ranges, as well as velocity field measurements by PIV.

Objective 3: study the behavior of biological fluids

These studies focus primarily on the behavior of medical fluids and their mixtures for applications in the field of infusions and injections, as well as the behavior of blood under thermal stress.

Morphologie des dépôts lors de l’évaporation de gouttes de sang sain et pathologique

Objective 4: study the dynamic behavior of droplets in microchannels

This work focuses on the analysis of the dynamic behavior of water droplets (or plugs) periodically dispersed in an oily phase within a rectangular T-junction microchannel, with a view to cooling applications for electrical systems, such as power electronics components, motors, transformers, batteries, DataCenters .... Among the set of parameters studied, particular attention is paid to the influence of the viscosity ratio (λ = μd / μc) as well as the effect of the microchannel wall temperature on plug dynamics, including their length, shape and velocity. The aim of this study is to gain a deeper understanding of the characteristic plug parameters that govern heat transfer efficiency within microchannels.

Keywords

Drops, microchannels, evaporation, boiling, surface tension, wettability, contact angle, microPIV, infrared microthermography, surface texturing, intelligent infusion systems, microheat exchanger, oils and emulsions.

Skills

Experimental analysis of fluid performance
Numerical simulation of two-phase flows at the micoscopic scale (microchannels, sessile drops ...)
Infrared thermography, micro PIV

Examples of work

Representative collaborations

VYGON
Centre Hospitalier de Valenciennes
University of Edinburgh

Equipment

Equipment name	Make	Specific information
Kruss optical droplet profile analyzer	KRUS	Goniometer
3 infrared cameras with spatial resolutions of 30, 15 and 3 mm	FLIR	Thermal cameras in the infrared
KEYENCE high-speed color camera VW-600C, Resolution 640 x 480 for 30 FPS and 160 x 32 for 230000 FPS, Magnification rate up to 500X	KEYANCE	CAMERA in the Visible
Micro-pump and micro-flow and pressure sensor set adapted to microfluidics	Elveflow