Système de chauffage de goutte basé sur l’interaction SAW-liquide

Droplet heating system based on SAW/liquid interaction

¹ Laboratoire de Physique des Milieux Ionisés et Applications (UHP-Nancy I)
² Laboratoire d’Energétique et de Mécanique Théorique et Appliquée (INPL-Nancy)

Auteur de correspondance : denis.beyssen@lpmi.uhp-nancy.fr

Abstract

In this study, Surface Acoustic Waves (SAW) / Liquid interaction (SAW streaming) was used to heat small droplet (few μl). SAW devices were designed on a 128° rotated Y-cut X-propagating LiNbO₃ 2” wafer with center frequency of 39,92 MHz. When the droplet is placed on the acoustic path, a longitudinal wave is radiated into the liquid. When SAW amplitude is sufficient, several phenomena can happen such as droplet actuation, internal flow into the droplet, atomisation. Recently, Kondoh et al. have demonstrate that irradiation of droplet by SAW is a powerful technique for heat small amount of liquid.Here, we want to quantify this effect (in static mode) in a wide range of viscosity as a function of SAW power which is correlated with SAW amplitude. We have worked with a non-contact infrared thermometer to measure droplet temperature and in order to explore wide range of viscosity Water-Glycerol mixture has been used.We notice that more droplet viscosity increase, more higher is the temperature. Finally, the liquid temperature can be controlled by the SAW power. A droplet can be consider as a micro-reactor because, it act both as a efficient mixer and fluidic thermocycler. This can be interesting for lab on chip.