颗粒是物质存在的普遍形式之一。当颗粒尺寸从宏观尺度减小到微观尺度时，颗粒的比表面积显著增加，从而赋予微颗粒独特的功能。由不同材料制成的形状和大小各异的微颗粒在化学合成、药物开发、体外诊断、图像显示、环境监测和治理等领域展现出巨大的应用价值，受到越来越广泛的关注。除材料性质外，微颗粒的形状和尺寸对颗粒的功能影响显著。微流控技术是一种多学科交叉的新型技术，能够在微尺度通道中实现对流体的精确控制和处理，为单分散多样化微颗粒的灵活制备提供了一类有效平台。

  液滴是微流控中常见的重要载体，具有不同形态的复合液滴在各种功能化微颗粒的制备上具有独特优势。我们首先设计了一种三相毛细管微流控芯片，通过控制流动模式以动态生成核-壳式或Janus液滴。该装置的主要优点是易于通过流速控制复合液滴的形态，从而合成具有特定结构的微颗粒。通过流动模式之间的转换，单一的轴对称毛细管微流控芯片能够调控生成核-壳式或孔-壳式微颗粒。我们展示了该装置在功能化微颗粒制造中的灵活性：保持颗粒外径不变，精确调控孔-壳式微颗粒的孔径；通过添加Fe₃O₄磁性纳米颗粒，可获得具有良好磁场响应的微颗粒。上述研究为不同形状复合微颗粒的制备提供了新方法。

  具有非常规形状的人造微马达颗粒应用日益广泛，但相关推进机制，特别是形状效应对气泡动力学和流动推进的影响机制几乎是空白。我们通过在微颗粒的凹面或凸面镀铂，制备了两种类型的碗状微马达颗粒，以研究曲面形状效应而产生的动力学行为。在低过氧化氢浓度的单气泡推进模式下，凹面镀铂微马达的运动速度出乎意料地慢于凸面镀铂微马达，而且凹面上气泡的生长速度也远慢于凸面情形。我们发现凹面的限制作用阻碍了过氧化氢反应物的补充，从而阻碍了催化反应。我们进一步引入了开尔文脉冲，阐明了凹面削弱气泡射流推进力的机制。而在高过氧化氢浓度下的多气泡模式下，气泡之间的相互作用呈现出“多即少”的现象，即过氧化氢浓度的增加并未提高最大瞬时推进速度。此工作为通过形状调控微马达驱动机制提供了研究基础，有助于人造微马达颗粒的设计。

  受界面张力的影响，在微通道中通过流体界面破碎的方法通常难以生成几十微米以下的液滴，从而限制了更小颗粒的制备。我们利用液-液相分离方法，在连续微流控芯片中生成了10微米以下的蛋白质凝聚体颗粒。通过蛋白质浓度和流速等参数的调节，能够精确控制蛋白质凝聚体的成核及生长过程。所形成的凝聚体有助于研究细胞复杂环境中无膜细胞器的形成机制及其与周围环境的生理活动。

Particles are one of the universal forms in which substances exist. When the size of particles decreases from macroscopic to microscopic scale, the ratio of surface area to volume of particles increases significantly, which endows microparticles with unique functions. Microparticles with different shapes and sizes made from different materials have been showing great applications and are of increasing interest in chemical synthesis, drug development, in vitro diagnostics, image display, and environmental monitoring and management. In addition to material properties, the shape and size of microparticles have a crucial impact on the functions of particles. As a novel multidisciplinary technology, microfluidics enables precise control and processing of fluids in microscale channels, providing a platform for the preparation of monodisperse diverse microparticles.

Droplets are a common and important class of carriers in microfluidics, and composite droplets with different morphologies provide unique advantages for the preparation of functionalized particles. We have developed a three-phase capillary microfluidic device by controlling the flow pattern to dynamically generate core-shell or Janus droplets. The main advantage of this device is the ease of controlling the morphology of the composite droplets by flow rate to obtain the synthesized microparticles with specific microstructure. By switching flow modes, a single axisymmetric capillary microfluidic chip is capable of generating either core-shell or hole-shell microparticles under well control. We further demonstrate the flexibility of the proposed device in the fabrication of functionalized microparticles: keeping the outer diameter of the particles unchanged, the pore size of the hole-shell microparticles can be precisely regulated; by adding Fe₃O₄ magnetic nanoparticles, microparticles with good magnetic field response can be obtained. This research provides a new method for the preparation of compound microparticles with various morphologies.

Artificial micromotor particles with unconventional shapes have been widely used, but the relevant propulsion mechanisms, especially the influence of the shape on bubble dynamics and flow propulsion, are almost unknown. We have fabricated two types of bowl-shaped micromotor particles by platinum plating on the concave or convex surfaces of the microparticles to investigate the dynamic behavior due to the shape effects of the curved surfaces. In the single bubble propulsion mode at a low hydrogen peroxide concentration, the motion of the concave platinum-plated micromotor is unexpectedly slower than that of the convex micromotor, and the growth rate of bubbles on the concave surface is also much slower than that on the surface of the convex surface. It is clarified that the confinement effect of the concave surface hinders the replenishment of hydrogen peroxide, thereby limiting the catalytic reaction. We further introduce Kelvin pulses to explain why the concave shape eventually weakens the propulsive force of the hydrodynamic jet induced by bubble collapse. In the multi-bubble propulsion mode at a high hydrogen peroxide concentration, the bubble interactions exhibit a "more is less" phenomenon - increasing the hydrogen peroxide concentration does not increase the maximum instantaneous propulsion speed. This work paves a way for regulating the driving mechanism of micromotors by shape, and is of help for the design of artificial micromotor particles.

Due to the influence of interfacial tension, it is difficult to generate the droplets of a dozen of microns or smaller size by interface fragmentation in microchannels. We develop a continuous microfluidic device to prepare protein condensate particles below 10 microns using the liquid-liquid phase separation method. The nucleation and growth process of the protein condensates can be precisely controlled by adjusting the concentration of protein and flow rates. This work provides a method for further studying the formation mechanism of membrane-less organelles in the complex environment of cells and their physiological activities with the surrounding environment.