Human blood cell separation using bulk acoustic waves in a machined PMMA microchannel

Abstract

Prior research demonstrated the separation of particles using bulk acoustic waves coupled from PZT (lead zirconate titanate) transducers into a PMMA (poly (methyl methacrylate)) prism containing a microfluidic channel. By directing fluid flow at an angle to a standing acoustic node field this device creates a field of drag and acoustic forces that separates particles based on both size and compressibility. This technology has been further developed both through rapid prototyping enabled by CNC (Computer Numerical Control) machining, and simulation in COMSOL Multiphysics 5.2a to enable the separation of human blood cells, and has been used to demonstrate the separation of red blood cells (RBCs) from white blood cells (WBCs), aggregated RBCs from free RBCs, and has shown different cell paths between stiffened RBCs and control RBCs. Applying this technology to human blood cell separations in the high-throughput, low-cost, low-volume device has potential as a point-of-care diagnostic tool. Specifically, the separation of RBCs from WBCs enables diagnosis of systemic infections; the separation of RBCs by differential compressibility enables diagnosis of parasitic RBC infection including malaria.