A New Microvalve for Piezoelectric Microfluidic Devices Activated by Surface Acoustic Wave

A new microvalve, which is comprised of microchannels, a microgroove and a piezoelectric substrate, is presented. An interdigital transducer with 27.5 MHz center frequency is fabricated on a 1280 yx-LiNbO3 piezoelectric substrate for exciting surface acoustic wave. The surface acoustic wave is used for changing the position of solid paraffin in main channel by heating the paraffin oil in the microgroove, and then controls the state of the microvalve. Red dye solution is used to demonstrate the operation of the microvalve and characterize the performance of the microvalve. The work is helpful for piezoelectric microfluidic devices for biochemical analysis.