介电泳微米粒子分离系统优化设计

There is a widespread need to separate microparticles with high efficiency and accuracy in chemical engineering, pharmaceutical, biomedical and relevant fields. Dielectrophoresis shows great potential in microparticle separation due to its demonstrated characteristics of continuity, label-free, high sensitivity and selectivity etc. However, the problem of low system throughput severely hinders the largescale development of this technique. In this project, a research strategy is carried out for scaling-up the dielectrophoretic separation system. Aimed at the problem that particle movements become more complicated in the enlarged dielectrophoretic system, a model of describing the multi-physics coupling and the particle motion in such a system is established, and a particle separator is design tailored for microparticle separation. The interaction between physical fields is revealed through dynamic simulation combined with experimental verification. The mechanism of particle motion and separation under the intervention of multi-physics is clarified, allowing precise control of the particle separation process. For the lack of a comprehensive evaluation means of particle separation in the enlarged system, a quantitative evaluation system is established. Key factors that affect the separation are determined and relations of the influence are quantified via system assessment. Using this as a basis, a system optimization model is proposed whilst the optimal separation strategy is formulated, enabling improved separation efficiency, accuracy and throughput with reduced system energy consumption. This project is expected to provide theoretical basis and optimal design for industrial applications of the dielectrophoretic microparticle separation.

高效精确分离微米粒子在化工、制药和生物医学等诸多领域有广泛的需求。介电泳技术以其连续性、样品免标记性、高敏感性和选择性等特点在微米粒子分离方面展示出巨大的潜力，然而低分离处理量问题严重阻碍了该方法的规模化发展。本项目拟开展将介电分离系统放大的策略研究。针对系统内粒子运动复杂化问题，构建准确描述放大介电系统内部多物理场耦合与粒子运动控制模型，设计适用于放大系统的粒子分离器；通过动态模拟与实验验证结合的方式，揭示物理场相互作用关系，阐明多物理场干预下粒子运动和分离控制机制，实现粒子分离过程的精准化控制。针对介电分离系统缺乏综合评价方法问题，建立分离定量评价指标体系；通过系统评价，确定影响分离的关键因素，量化影响关系；在此基础上构建系统优化模型，制定最优分离策略，提高介电分离效率、精度和处理量，降低系统能耗。本项目研究将为介电泳微米粒子分离技术工业化应用提供理论分析基础和优化设计方案。

高效精确分离微米粒子在化工、制药和生物医学等诸多领域有广泛的需求。介电泳（DEP）技术以其连续、样品免标记、高敏感性和高选择性等特点在微米粒子分离方面展示出巨大的潜力，然而极低分离处理量问题严重阻碍了该方法的规模化应用。为此，本项目采用将介电系统放大的研究策略，解决介电泳微米粒子分离过程的低样品处理量问题。面对放大介电系统内粒子运动复杂化和焦耳热副作用显著化问题，项目创新性的构建了系统内电场、流场、和温度场耦合与粒子运动控制模型，创新性的首次将焦耳热引发的电热流和浮力流对粒子的共同作用引入模型，通过动态模拟，阐明了粒子在放大介电系统内多物理场作用下的分离机理，实现了微米粒子在系统内运动和分离过程的精准控制。基于模型和模拟，项目对三种介电微米粒子分离器和对应的分离系统进行了优化设计。其中混合浮动介电分离器采用叉指圆柱电极的混合浮动排列的设计方式以减少焦耳热的影响和分离降低系统能耗，理论分离处理量最高可达2.4mL/min；平板浮动介电分离器采用平板和浮动电极相对排列设计使得交流电热与DEP协同作用于粒子分离，在最大化利用焦耳热的同时提高了粒子的分离效率和精度，对于5,10,15微米聚苯乙烯粒子的分离效率可达99.9%；同轴型介电分离器采用中央集中电极排列方式，内置径向位置可调的收集管，在保证分离效率的基础上将样品处理量进一步提高至6mL/min；项目提出的几种分离器相比现有报道的介电微系统分离器，在同等的分离精度下最大样品处理量有数百倍的提升，加之通过对分离系统内参数的优化设计，有效降低了分离过程能耗。综上，本项目研究可为介电泳微米粒子分离技术的工业化应用提供理论基础和优化方案。