Impact of Bubbles on the Near-Wall Flow in Microchannels

0444682 - ÚCHP 2016 SK eng C - Conference Paper (international conference)
Tihon, Jaroslav - Pěnkavová, Věra - Stanovský, Petr - Vejražka, Jiří
Impact of Bubbles on the Near-Wall Flow in Microchannels.
Proceedings of the 42nd International Conference of SSCHE. Bratislava: Slovak Society of Chemical Engineering, 2015 - (Markoš, J.), s. 83. ISBN 978-80-89475-14-8.
[International Conference of Slovak Society of Chemical Engineering /42./. Tatranské Matliare (SK), 25.05.2015-29.05.2015]
R&D Projects: GA MŠMT(CZ) LD13018
Institutional support: RVO:67985858
Keywords : microchannel flow * taylor bubbles * near-wall flow
Subject RIV: CI - Industrial Chemistry, Chemical Engineering

The electrodiffusion technique has been mostly used for the near-wall flow diagnostics on large scales. A novel technique for fabrication of plastic microfluidic systems with integrated metal microelectrodes (called technique of sacrificed substrate) enables us to produce microfluidic devices with precisely shaped sensors for wall shear stress measurements. Several micrometer thick gold sensors, which are built-in a plastic substrate, exhibit good mechanical resistance and smoothness. Proper functioning of prepared chips with microsensors has been first tested in various calibration experiments (polarization curve, sensor response to polarization set-up, steady flow calibration, temperature dependence of diffusivity). Our first results obtained for gas-liquid Taylor flow in microchannels demonstrate its applicability for the determination of wall shear stress response to moving bubbles. Other applications of these sensors in microfluidics (e.g. characterization of liquid films, capillary waves, bubbles or drops) can be also envisaged.
Permanent Link: http://hdl.handle.net/11104/0247197