A power-free blood plasma extraction device based on planar crossflow filter microstructure

This paper presents a simple blood plasma extraction device without any external driving force for point-of-care diagnosis. On the basis of capillary phenomenon and size exclusion, blood plasma was extracted through a planar crossflow filter using a surfactant-added poly(dimethyl siloxane)(PDMS) and SU8-based microstructure. The wetting property of PDMS was modified by mixing PDMS with nonionic surfactant, Silwet L-77. As a demonstration of the feasibility of this device, the contact angles and capillary filling rates according to the concentration of surfactant in PDMS were compared and the extraction of plasma from whole blood was confirmed through the planar filter with various heights.