State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
J Chromatogr A. 2023 Nov 22;1711:464434. doi: 10.1016/j.chroma.2023.464434. Epub 2023 Oct 6.
Pillar shape exploration in deterministic lateral displacement (DLD) technique holds great promise for developing high-performance microfluidic devices with versatile sorting schemes. A recent innovative design using filter-like micropillars was proposed to improve cell separation, but its significance might be greatly underestimated due to an inaccurate understanding of the underlying mechanism. In this study, we employ mesoscopic hydrodynamic simulations to explore the movement and separation of rigid spherical particles in DLD arrays using various two-piece hybrid (TPH) pillars, where each pillar consists of two individual pieces separated by a tunable inter-piece channel. In comparison with the conventional one-piece pillars, the back piece of TPH-pillars is found to hierarchically tailor the flow profile of the front piece on the basis of the row shift fraction and the inter-piece channel width, resulting in unique tunable multi-scheme separation at low, intermediate, and high row shift fractions, respectively. At the intermediate regime, in particular, the first flow lane that determines the critical separation size could be physically fenced out by the inter-piece channel, and a delicate coupling of hydrodynamic filtration and DLD has been revealed to induce a constant critical size in the whole regime. This work theoretically demonstrates the feasibility and significance of TPH-pillars, which may open up a new direction of the geometry design by exploiting rich multi-piece hybrid structures to expand the versatility of the DLD technique.
在确定性侧向位移（DLD）技术中，探索柱状结构具有很大的潜力，可以开发出具有多种分选方案的高性能微流控器件。最近提出了一种使用类似滤波器的微柱的创新设计，以提高细胞分离效率，但由于对其潜在机制的理解不准确，其重要性可能被大大低估。在本研究中，我们采用介观流体动力学模拟，使用各种两段式混合（TPH）柱状结构来研究刚性球形粒子在 DLD 阵列中的运动和分离，其中每个柱状结构由两个通过可调节的柱间通道分离的独立部分组成。与传统的一体式柱状结构相比，TPH 柱状结构的后段基于行移位分数和柱间通道宽度，对前段的流型进行分层调整，从而在低、中和高行移位分数下分别实现独特的可调多方案分离。特别是在中间区域，第一个决定临界分离尺寸的流道可以被柱间通道物理隔离，揭示了一种精细的流体动力学过滤和 DLD 耦合，可在整个区域诱导恒定的临界尺寸。这项工作从理论上证明了 TPH 柱状结构的可行性和意义，通过利用丰富的多段混合结构，可以为 DLD 技术的通用性设计开辟新的方向。
