非对称铌酸锂夹层结构中微液滴的光热复合实时操控研究

Optical microdroplet manipulation is the key photonic function of a biological Lab-on-a-LN-chip, and it usually applies to the non-contract actuation, guiding and splitting of biochemical agent and biologic droplets. The applicant found in previous researches that, the liquid nature of microdroplets makes their manipulation quite flexible, especially by using the combination of different substrates. Moreover, the temporal photo-thermo-excited charge field involved in the manipulation introduces a lot of novel behaviors of the microdroplets. . The present project is to further study the in-situ photo-thermo-assisted manipulation of the microdroplets in an unsymmetrical sandwich structure of LN substrates. In the project microdroplet manipulation effect will be studied systematically by varying the experimental conditions, a multiphysical model for the space charge generation in LN will be developed considering the coupling effect between the photoelectricity and pyroelectricity. Finally, the mechanism of photo-thermo-assisted microdroplet manipulation will be deduced and applied to the optimization of the LN sandwich structure.. In this project, three novel manipulation ways for dielectric microdroplets will be investigated: the guiding actuation of microdroplets by using pre-scanning, the all-optical splitting of microdroplets, and the non-local manipulation of microdroplets. Besides, the project also aims to develop the manipulation technique for aqueous microdroplets by using LN substrates coated with dielectric layers. The project is of an importance to the low-cost and efficient biochemical analyses of the Lab-on-a-LN-chip in the future.

微液滴光操控功能是铌酸锂基生物光子芯片的重要核心功能，可用于生化试剂及生物液滴的非接触驱动、导向和分离。申请人在前期工作中发现微液滴的流体本质可以使微液滴的光操控模式通过非对称的衬底组合变得非常灵活，同时微液滴实时操控所涉及的光热复合瞬态电荷场会使微液滴呈现出很多新颖的操控行为。.本项目进一步深入研究非对称铌酸锂夹层结构中微液滴的光热复合实时操控，通过系列实验寻找各类典型微液滴操控模式下操控效果随实验参数的变化规律；考虑操控光场下光生电荷及热释电荷的综合贡献,建立光场、热场、电场多物理场耦合的铌酸锂光热复合生电模型；推断各类典型液滴操控模式的具体微观机制并用于优化铌酸锂夹层结构。.本项目重点研究三种新型介电微液滴操控模式：预扫描二维导向驱动、全光可控分离和非局域光操控，此外还研究介质层修饰的铌酸锂夹层中水合微液滴的光操控。本项目研究对于未来生物光子芯片低消耗、高效率的生化检测具有重要意义。

微液滴光操控功能是铌酸锂基生物光子芯片的重要核心功能，可用于生化试剂及生物液滴的非接触驱动、导向和分离。本项目围绕铌酸锂基微流体的操控模式开发和效果调控，光伏、热释电复合模型建立和相关静电操控机制研究，以及面向未来铌酸锂基生物光子芯片的微液滴操控参数优化和功能设计，开展了一系列的基础性工作，并取得以下结果：1）利用反对称配置的双y切掺铁铌酸锂夹层结构实现了介电微液滴的全光分离操控，且分离时间可由光强调控。2）通过热辅助下铌酸锂表面形成的热释电场和激光预扫描形成的光伏电场的复合，在铌酸锂夹层结构中实现了分立相介电微液滴沿扫描路径的往复运动以及连续相液体沿扫描路径的高分辨图案化。3）在铌酸锂表面上实现了水合气流轨迹的光伏瞬态操控和液化凝结，并阐明光致液化凝结的机制。4）在油浸疏水异质衬底上利用铌酸锂表面光伏场实现了对低阻水合微液滴的远距离隔空驱动，并提出了水合微液滴光伏操控失效的关键因素：高光伏电场下水合微液滴界面发生瑞利喷射所导致的介电泳-电泳作用转变。5）发展出一个光场、热场、电场多物理场耦合的铌酸锂光热复合生电模型，明确指出聚焦激光辐照下光伏场对微液滴光操控行为起主导作用。6）在y切铌酸锂油浸疏水表面上实现了水合液滴的光伏分离，揭示了介电润湿和电渗效应在液滴分离中的协同作用；在c切铌酸锂油浸疏水表面上实现了水合微液滴的高效光伏输送，并借助光伏往复运动模式实现了水合液滴对荧光染料的可控微量重复获取。7）以铌酸锂为衬底构建了水合微液滴光伏路由器，将液滴在超疏水表面的摩擦带电效应与铌酸锂表面的光伏场相结合，利用库伦作用实现水合微液滴在3D空间中的高效级联输运。8）在铌酸锂基PDMS通道中实现了水合微液滴的非局域一维光伏驱动。该技术避免了操控激光对生物液滴的直接照射，成功应用于微通道内的沉淀、显色化学微反应以及生物实验。