An integrated microfluidic chip with 40 MHz lead-free transducer for fluid analysis

The design, fabrication, and evaluation of a high-frequency transducer made from lead-free piezoceramic for the application of microfluidic analysis is described. Barium strontium zirconate titanate (Ba0.95Sr0.05)(Zr0.05Ti0.95)O3, abbreviated as BSZT ceramic has been chosen to be the active element of the transducer. The center frequency and bandwidth of this high-frequency ultrasound transducer have been measured to be 43 MHz and 56.1%, respectively. The transducer was integrated into a microfluidic channel and used to measure the sound velocity and attenuation of the liquid flowing in the channel. Results suggest that lead-free high-frequency transducers could be used for in situ analysis of property of the fluid flowing through the microfluidic system.