Understanding Microbeads Stacking in Deformable Nano-Sieve for Efficient Plasma Separation and Blood Cell Retrieval

Efficient separation of blood cells and plasma is key for numerous molecular diagnosis and therapeutics applications. Despite various microfluidics-based separation strategies have been developed, a simple, reliable, and multiplexing separation device that can process a large volume of blood is still missing. Here we show a microbead packed deformable microfluidic system that can efficiently separate highly purified plasma from whole blood as well as retrieve blocked blood cells from the device. Combining microscope imaging, optical tomography scanning, and computational fluidic modeling, a highly accurate model is constructed to understand the link between the mechanical properties of the microfluidics, flow rate, and microbeads packing/leaking, which supports and rationalizes the experimental observations. This deformable nano-sieve device establishes a key technology for centrifuge-free diagnosis and treatment of bloodborne diseases and may be important for the design of next-generation deformable microfluidics for separation applications.