Acoustically driven microfluidic applications for on-chip laboratories

Employing surface acoustic waves (SAW), we induce acoustic streaming within minute amounts of fluid on a planar piezoelectric chip. Apart from the SAW generating interdigital transducers, this chip can also be equipped with various other functional elements like heaters, sensors and alike. Because the SAW driven micro fluidic system can be electrically addressed, we end up with a fully programmable micro laboratory for chemical and biological applications. Depending on the amplitude of the SAWs, the acoustic streaming can be very efficiently used to mix and stir the fluids, or - at higher amplitudes- to actively actuate whole droplets or closed fluid volumes across the chip surface. Various applications are given, which demonstrate the uniqueness and power of our approach.