An Implementation of a Microfluidic Mixer and Switch Using Micromachined Acoustic Transducers

This paper presents the results of fluidic switching and mixing, performed in microfluidic channels, integrated with micromachined acoustic transducers. The transducers operate at 400 MHz while the microfluidic channels are made by casting polydimethylsiloxane (PDMS) on silicon moulds. Rapid switching is incorporated by applying pressure waves in one of the two outlet channels to get preferential flow. Radiation pressure is also utilized to obtain active mixing of fluids within the channel. This method of switching and mixing has the advantages of simple design and ease of integration into larger systems.