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 having been developed, there is still a need for a simple, reliable, and multiplexing separation device that can process a large volume of blood. 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. To support and rationalize the experimental validation of the proposed device, a highly accurate model is constructed to help understand the link between the mechanical properties of the microfluidics, flow rate, and microbeads packing/leaking based on the microscope imaging and the optical coherence tomography (OCT) scanning. This deformable nano-sieve device is expected to offer a new solution for centrifuge-free diagnosis and treatment of bloodborne diseases and contribute to the design of next-generation deformable microfluidics for separation applications.