Complex Surface Acoustic Wave Fields for Microfluidic Applications
* Presenting author
Abstract:
Surface acoustic waves (SAW) are predestined for the active manipulation of fluids as well as of immersed particles or cells in microfluidic lab-on-a-chip systems. The generation of driving forces in the fluid originally rests upon the lateral distribution of the complex displacement amplitude, i.e. the surface acoustic wave field. Here, we present numerical and experimental results of complex wave field analysis and discuss underlying effects of SAW excitation and propagation on anisotropic, piezoelectric substrates. Furthermore, a novel mechanism for the active manipulation of the polarization of surface acoustic waves is demonstrated that is of particular interest for SAW-driven microfluidics because it enables a more precise control of fluid actuation and also shows the potential to efficiently reduce losses due to undesirable dissipation of acoustic energy. In general, the combination of theoretical and experimental investigations provides a deeper insight into fundamental effects of acoustofluidic coupling and allows for the realization of tailored SAW-based microfluidic actuators.