电场调控液态金属泵送生物流体的机理及其在微流控片上器官中的应用

Conventional fluid driving methods are unable to meet the demands when utilized for pumping biofluid in organ-on-a-chip platforms, and it becomes the bottleneck that hindering the advance of organ-on-a-chip systems. Since the novel liquid metal material, gallium eutectic alloy, has the properties of both metal and liquid, it shows great potential for driving fluid in electric field, and thus it is of strong possibility to be utilized for pumping biofluid in organ-on-a-chip. Therefore, by combining the nano- and micro-scale researching methods, we will at first research on the nano-scale charging behavior of the electrical double layer (EDL) at the liquid mental- electrolyte interface, and build the physical model in different situations. Subsequently, we will investigate the coupling mechanism among the electrochemical polarization, continuous electrowettig and continuous two-phase flow, in order to explain the trans-scale relationship between the nano-scale EDL charging and the micro-scale liquid flowing. After that, we will conduct biofluid pumping experiments using liquid metal with different parameters, and so amend the theoretical formula. Moreover, we will look into how different compositions in biofluid would affect the pumping performance, and investigate the flow property of multistage pumping. Finally, we will apply the liquid metal pump into the organ-on-a-chip culturing and drug testing platform. This project involves research on basic mechanism of manipulating liquid metal in electric field, and accordingly will provide theoretical basis for the practical application of the novel liquid metal enable pump.

传统流体驱动形式难以满足片上器官中生物流体的多种泵送要求，成为制约片上器官发展的瓶颈。新型镓合金液态金属材料兼具金属和流体的双重特性，在电场调控下具有优异的流体驱动潜能，有望实现片上器官中生物流体的泵送目标。为此，本项目采用纳观-微观相结合的方法，首先研究液态金属/电解液界面纳米尺度双电层的充电动力学行为，建立不同条件下液态金属表面双电层的充电模型；在此基础上，揭示液态金属表面电化学极化-连续电润湿-两相流流动的耦合机理，明确纳米尺度双电层充电与微米尺度流体流动之间的跨尺度关系；随后，开展不同参数条件下利用液态金属进行生物流体泵送的实验研究，修正理论公式；研究生物流体多种成分对液态金属泵送能力的影响，同时探究多级泵组合的流体控制特性；最后，开展液态金属泵在片上器官培养与药物试验中的应用研究。本项目涉及电场调控液态金属的本源，将为新型液态金属泵送方法的广泛应用提供理论依据。

传统流体驱动形式难以满足片上器官芯片中生物流体的多种泵送要求，已成为限制其向集成化和小型化发展的最大阻碍之一。新型镓基合金液态金属材料兼具金属和流体的双重特性，其在电场调控下产生的电致马朗格尼效应具有优异的流体驱动潜能，有望实现片上器官芯片中生物流体的泵送目标，并为微流控芯片流体驱动形式设计提供新的思路。为此，本项目采用纳观-微观相结合的方法，首先研究了液态金属液滴/电解液界面纳米尺度双电层的充电动力学行为，开展了对如离子液体，噬铝反应等非常规情况下液滴表面双电层电荷异常分布现象研究，建立不同条件下更加完善的液态金属液滴表面双电层的充电模型；在此基础上，揭示液态金属表面电化学极化-连续电润湿-两相流流动的耦合机理，明确纳米尺度双电层充电与微米尺度流体流动之间的跨尺度关系；推导了液态金属液滴表面双电层最终表面电势公式，电毛细应力公式及流速分布公式；随后，设计并开展了多种利用镓基液态金属液滴进行生物流体泵送的实验研究方案，利用实验数据进一步修正理论模型公式；研究多种流体成分对液态金属泵送能力的影响，同时探究多级泵组合的流体控制特性；最后，开展基于液态金属的电驱动泵在片上器官肿瘤细胞动态培养中的应用研究，进一步模拟体内真实流动生存环境。本项目以电场调控镓基液态金属的基本理论及实验论证作为研究重点，将为新型镓基液态金属泵送方法的广泛应用提供理论依据，同时研究中所设计的不同形式的液态金属微泵对探索肿瘤细胞对靶向药物或化疗药物的敏感性以及建立肿瘤联合治疗方法具有重大意义。