Droplets transport together with a small steel ball driven by surface acoustic waves

A new method for transporting microfluid was presented. An interdigital transducer was fabricated on an YX-128° LiNbO3 piezoelectric substrate for generating surface acoustic wave (SAW). A sample droplet is placed on a small steel ball, which is driven by the SAW. Temperature characteristics of the sample droplet are theoretically analyzed, and experimentally verified. Red ink solution is demonstrated for sample droplet transport. The presented transport method is successfully applied in color development reaction. Compared to traditional SAW driving droplets, the equilibrium temperature of sample droplet driven by presented method is decreased 11.8 °C at 30.9 dBm of electrical signal power.