Separation of platelets from whole blood using standing surface acoustic waves in a microchannel

Abstract

Platelet separation from blood is essential for biochemical analyses and clinical diagnosis. In this article, we propose a method to separate platelets from undiluted whole blood using standing surface acoustic waves (SSAWs) in a microfluidic device. A polydimethylsiloxane (PDMS) microfluidic channel was fabricated and integrated with interdigitated transducer (IDT) electrodes patterned on a piezoelectric substrate. To avoid shear-induced activation of platelets, the blood sample flow was hydrodynamically focused by introducing sheath flow from two side-inlets and pressure nodes were designed to locate at side walls. By means of flow cytometric analysis, the RBC clearance ratio from whole blood was found to be over 99% and the purity of platelets was close to 98%. Conclusively, the present technique using SSAWs can directly separate platelets from undiluted whole blood with higher purity than other methods.

Cell separation using tilted-angle standing surface acoustic waves

“…When separating cells with distinct physical properties, using methods that exploit differences in cells' physical parameters could be advantageous due to their label-free nature and ease of use (11,12). Many techniques are available to separate cells based on physical properties; they include filtration, centrifugation, acoustics, optics, and dielectrophoresis (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). Among these techniques, acoustic-based approaches are advantageous because of their biocompatibility and label-free nature (25,(27)(28)(29)(30)(31)(32).…”

Continuous sheathless microparticle and cell patterning using CL-SSAWs (conductive liquid-based standing surface acoustic waves)

“…in a non-invasive way and are thus more versatile than electrical fieldbased techniques for various applications, including focusing, patterning, separation and enrichment of particles or cells. 4,[21][22][23][24][25][26][27][28] However, complicated fabrication technique or skilled bonding process using additional chemical and an apparatus are required to facilitate the parallel alignment between the microfluidic channel and the patterned metal electrodes on the piezoelectric substrate, 29,30 which can hinder wide applications of the conventional SSAW device.…”

Particle manipulation using macroscale angled ultrasonic standing waves

“…Angled acoustic surface waves have been used for cell sorting with some success. [12][13][14][15][16][17][18][19][20] These systems still have some limitations relating to microfluidic sized channels and low flow rates. Such angled wave systems have potential over conventional concepts since the axial radiation force component is used only to deflect, rather than stop particles.…”