Particle separation using surface acoustic waves based on microfluidic chip

Surface acoustic wave (SAW)-based microfluidic particle separation offers exceptional biocompatibility and precision for biological applications. This study establishes a multiphysics coupling model integrating piezoelectric dynamics, acoustic-structural interactions, and fluid-particle mechanics to optimize SAW separator design. Systematic analysis of interdigital transducer geometry and flow-acoustic coupling reveals that electrode width governs acoustic wavelength distribution, with 50 μm electrodes achieving optimal pressure gradients. Increasing electrode pairs (N = 5) enhances acoustic pressure inversion, while applied voltage (20 V) proportionally amplifies radiation forces. Notably, channel height exhibits negligible impact on the acoustic field. The optimized device achieves efficient separation of 5–15 μm particles through synergistic flow focusing and acoustic node alignment. This work provides a systematic framework for high-purity biological particle separation, advancing SAW-based microfluidics in diagnostics and cellular analysis.