Optimization of Serpentine Microfluidic Chip Integrated by Sharp-Corner-Based Microstructure

Abstract

This study presents a systematic optimization of sharp-corner microstructures integrated into a "Christmastree" architecture to overcome diffusion-limited mass transport in low-Reynolds-number regimes, enabling rapid and homogeneous mixing within complex branching networks for high-throughput microfluidic gradient generators. Through a bidirectional co-simulation workflow between SolidWorks and COMSOL Multiphysics, we map the non-linear coupling between geometric parameters, i.e., the sharp-corner width and height, and the resulting mixing performance. Analysis of the global design space reveals a multi-peaked landscape, facilitating critical distinction between physically viable structural optima and numerical "pseudo-optima" plagued by deleterious flow separation and stagnant dead zones. The structural optimum is identified at a height of 0.16 mm and a width of 0.1 mm, where induced transverse secondary flows maximize concentration homogenization while preserving hydrodynamic integrity. This study provides a robust methodological reference for the automated design of passive microfluidic modules, ensuring reliable gradient generation for next-generation lab-on-a-chip applications.