A Universal and Single-Step (De)Molding Sorting Chip Integrating Inertial and Deterministic Lateral Displacement Units.

Serum tests are valuable sources of information for disease diagnosis. Conventional whole blood cell separation requires many processing steps, including centrifugation, fractionation, lysis, and dilution, and is therefore complex and time consuming. To address the need for the efficient separation of blood cells for on-chip rapid serum assays, we developed a microfluidic chip integrating inertial sorting and deterministic lateral displacement. This chip consists of a helical structure and a deterministic lateral displacement triangular microcolumn array for rapid and efficient separation of blood cells from whole blood samples. After separation, the supernatant is extracted at the exit for subsequent testing or directed to serum test units directly integrated in the chip. Here, the laminar flow and transport modules are coupled using finite element analysis for both multi-component and discrete-phase physical fields to simulate blood flow characteristics in the chip. The influences of flow rate and flux ratio on the sorting efficiency of blood cells were also discussed. Simulation results determined that the microfluidic chip designed in this research can achieve a cell sorting efficiency greater than 98% at suitable flow rates. Experimental results similarly achieved a high sorting effect of above 96%. Therefore, this blood cell sorting microfluidic chip shows strong potential for rapid serum testing applications and can be integrated as a stand-alone blood cell sorting module for various on-chip serum testing systems used to diagnose diseases.