Caractérisation de la charge de surface de systèmes microfluidiques en PDMS par mesures de courants d’écoulement

Surface charge determination by streaming current measurement in PDMS microfluidic systems

¹ Laboratoire d’Electronique Nanotechnologies Capteurs (LENAC) Université Claude Bernard Lyon 1
² Laboratoire de Physique de la Matière Condensée et Nanostructures Université Claude Bernard Lyon 1

Auteur de correspondance : louis.renaud@lenac.univ-lyon1.fr

Abstract

The surface charge of a microfluidic system is a very important experimental factor, because the electroosmotic flow (and the separation efficiency) depends directly on it. So, the characterization of this parameter is very interesting. Some measurement methods of this surface charge already exist, but take generally a long time to be exploited. A more original method, by measurements of currents of flow is used here. The material which has here interested us is the PDMS, polymer largely used into microfluidic today. The surface charge of the PDMS was measured according to two important parameters: the relaxation time of the surface after plasma O2 oxidation, and the pH of the electrolyte filling the microchannels.