Particle Manipulation by Means of Piezoelectric Actuators for Microfluidic Applications

In this paper the possibility to generate acoustic waves such as FPW (Flexural Plate Wave) for fluid and particle manipulation by piezoelectric actuators applied on non-piezoelectric substrates is explored. A test device with two Lead Zirconate Titanate (PZT) actuators deposited on an alumina (Al2O3) substrate by screen printing technique is presented. The experimental results show that, by exciting the actuators at their resonance frequencies, FPW modes are generated in the substrate. Circular vortex rotations are obtained in a fluid drop placed on the substrate by exciting a single actuator. In addition, micrometric particles dispersed in the drop allow to demonstrate that particle accumulation along circular lines is obtained by exciting both the actuators. These results suggest the possibility to employ the proposed actuators for fluid mixing and controlled positioning of dispersed particles.