Non-Contact Micro-Liquid Mixing Method Using Ultrasound

Abstract

A new mixing method for micro-liquid has been developed. In the new method, a radiation pressure of ultrasound is used to stir liquid in a vessel without any physical contact. The developed mixing device based on the method consists of a vessel containing the liquid to be mixed and two ultrasound sources (frequency: 1.6 MHz) arranged outside the vessel. One of them radiates through the bottom, the other through the side wall of the vessel. The latter sound source is divided into several segments. And the fine position of the sound source corresponding to the level of liquid is adjusted by selecting the appropriate segments. The mixing performance is evaluated according to the difference between the two local transmissibilities of laser beam in the liquid. As a result, we confirmed that by using the mixing device, the liquid (80 -160 µL of water and dye) become homogeneous within 1.0 sec.

Ultrasound assisted liquid–liquid extraction in microchannels—A direct contact method

“…Many methods have been developed to increase the mixing effects in a microreactor which are broadly classified as active and passive ones 6 . Ultrasound is an example of the active approach, providing a non-contact method of mixing 7 within the very small structures of the microreactor. The advantages of using ultrasound in chemical synthesis and in microstructured devices for multiphase flow have been reported in literature [8][9][10][11][12][13] .…”

Temperature controlled interval contact design for ultrasound assisted liquid–liquid extraction

“…In the last decade, ultrasound has gained momentum in relation with micro-or milli-structured devices for the use in chemical processes (Fernandez Rivas et al, 2012;Fernandez Rivas and Kuhn, 2016). This interest originates from its ability of being a non-contact source to activate or initiate physical (Cravotto and Cintas, 2012Katou et al, 2005;Linares et al, 1987;Okadap et al, 1972;Suslick et al, 1990) or chemical effects (Cravotto and Cintas, 2006; Leonelli and Mason, 2010;Mason, 2000;Suslick et al, 1990). These effects are a result of the cavitation induced by the ultrasound in the liquid medium and are documented to contribute to many factors such as improved mass transfer characteristics (Ahmedomer et al, 2008;Monnier et al, 2000Monnier et al, , 1999Okadap et al, 1972).…”