Jiang Hao, Zhang Fengyang, Fan Zhou, Zhang Chundong, Zhang Zunmin
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
Micromachines (Basel). 2025 Apr 30;16(5):546. doi: 10.3390/mi16050546.
Deterministic lateral displacement (DLD) has emerged as a powerful microfluidic technique for label-free particle separation with high resolution. Although recent innovations in pillar geometry have broadened its biomedical applications, the fundamental mechanisms dictating flow behavior and separation efficiency remain not fully understood. In this study, we conducted dissipative particle dynamics simulations to systematically investigate the separation of rigid spherical particles and red blood cells (RBCs) in DLD arrays with inverse L-shaped pillars. The simulations established a predictive formula for the critical separation size in such devices and demonstrated that inverse L-shaped pillars enabled a reduced critical separation size compared with conventional circular pillars. Additionally, we revealed that the inverse L-shaped pillars could act as deformability sensors, promoting localized RBC deformation near their protrusions and inducing stiffness-dependent bifurcation in cell trajectories, which enables effective sorting based on cell deformability. These findings advance the mechanistic understanding of inverse L-shaped DLD arrays and provide valuable design principles for their potential applications.
确定性侧向位移（DLD）已成为一种强大的微流控技术，可用于高分辨率的无标记颗粒分离。尽管最近柱体几何形状的创新拓宽了其生物医学应用，但决定流动行为和分离效率的基本机制仍未完全理解。在本研究中，我们进行了耗散粒子动力学模拟，以系统地研究具有倒L形柱体的DLD阵列中刚性球形颗粒和红细胞（RBC）的分离。模拟建立了此类装置中临界分离尺寸的预测公式，并表明与传统圆形柱体相比，倒L形柱体能够减小临界分离尺寸。此外，我们发现倒L形柱体可以作为可变形性传感器，促进其突出部附近的红细胞局部变形，并在细胞轨迹中诱导刚度依赖性分叉，从而实现基于细胞可变形性的有效分选。这些发现推进了对倒L形DLD阵列的机理理解，并为其潜在应用提供了有价值的设计原则。
