液-液相分离指均匀液相在特定条件下，自发分离为两个或多个不同液相的 过程。这种现象不仅广泛存在于物理、化学领域，同时作为蛋白质等生物大分 子组装成具有功能性的微液滴及无膜细胞器的基础，是生命体功能调控的一种 极为普遍的方式。蛋白质等生物分子能够通过相分离自组装成纳米至微米尺度 的功能性液滴，通过液-液界面封装并富集特定的生物分子形成无膜的细胞隔室， 即所谓的无膜细胞器。这一过程使得液滴内的生化反应能够精确调控，并通过液 体界面与细胞质进行快速物质交换。尽管细胞内相分离液滴的存在已被广泛确 认，但我们对其形成机制和过程的理解仍然相对有限。 因此，本文针对生物大分子相分离动力学及调控中的两个关键科学问题：相 分离液滴时空动态观测及调控方法、生物相分离液滴的生长机制及调控规律展 开了相关的工作。本研究构建了基于微流控技术的体外生物相分离实验方法，提 供了一个动态观测和定量表征生物大分子相分离过程的体外系统，在此基础上， 本研究定量地研究了PGL-3蛋白质在流固界面上相分离液滴的成核和生长动力 学过程，实现了通过调控盐离子浓度以及蛋白质之间的相互作用来控制相分离 液滴的成核速率，并发现相分离液滴的力学性质影响其生长标度率。本研究从微 纳米流体力学视角，为深入理解生物大分子微液滴在复杂环境中的形成机制提 供了研究基础。

Liquid-liquid phase separation refers to the process in which a homogeneous liq uid phase spontaneously separates into two or more distinct liquid phases under specific conditions. This phenomenon is prevalent in physics and chemistry and serves as a fun damental mechanism bywhichbiomolecules, such as proteins, assemble into functional microdroplets andmembranelessorganelles, providingahighlycommonmeansoffunc tional regulation within living organisms. Proteins and other biomolecules can self assemble into functional droplets at nano- to micrometer scales through phase separa tion, forming membraneless cellular compartments known as membraneless organelles byencapsulating and enriching specific biomolecules at the liquid-liquid interface. This process enables precise regulation of biochemical reactions within droplets and allows rapid material exchange with the cytoplasm across the liquid interface. Although the presence of phase-separated droplets within cells is widely recognized, our understand ing of their formation mechanisms and processes remains relatively limited. Therefore, this paper addresses two key scientific questions in the dynamics and regulation of biomolecular phaseseparation: thespatiotemporalobservationandregula tion of phase-separated droplets, and the growth mechanisms and regulatory principles of biological phase-separated droplets. This study establishes an in vitro experimental method for biological phase separation based on microfluidic technology, providing a system for dynamicobservation and quantitative characterization of biomolecular phase separation processes. Building on this, the research quantitatively investigates the nu cleation and growth kinetics of PGL-3 protein phase-separated droplets on a flow-solid interface, achieving control over nucleation rates by modulating ionic concentration and protein interactions. It was also found that the mechanical properties of phase-separated droplets affect their growth scaling rate. This research, from the perspective of micro nanofluidics, lays a foundation for a deeper understanding of the formation mechanisms of biomolecular microdroplets in complex environments.