Decrescendo Spiral Microfluidic Channel: Secondary Flow Enhancement for Efficient Microparticle Separation

Abstract

This study presents a Decrescendo spiral microfluidic chip designed to enhance inertial focusing and size-based particle separation under high-throughput conditions. The asymmetric channel geometry combines a narrowing upper layer with a rectangular lower channel, inducing strong secondary flow toward the inner wall. This design amplifies Dean vortices and enables stable particle focusing across wide flow rates. Simulations and fluorescent bead experiments confirmed improved performance, achieving recovery rates of 96.2%, 93.3%, and 93.1 % for 4.1,6.3, and 15.0 μ m beads, respectively, demonstrating high efficiency for microparticle separation. © 2026 IEEE.