自驱微生物与聚合物的混合溶液广泛存在于自然界与实验室中。其流体力学相互作用主导了溶液诸多性质。当前学术界针对微生物与小颗粒混合体系进行了大量的实验观察、数值模拟与理论分析，然而对更复杂的、具有内部多自由度的聚合物体系，尚缺乏可靠的数值模拟与理论模型。本项目拟针对此混合溶液开展数值研究与理论分析，力图揭示流体力学相互作用对体系结构与动力学演化的重要意义。我们将重点研究混合溶液的两个关键性质：1）聚合物分子的形态转变与动力学性质。包括其在溶液中的屈曲、翻转、迁移与扩散。2）自驱微生物在聚合物溶液中的运动。包括加速、减速以及转向。方法上，本项目拟发展斯托克斯点力方法和含流体的布朗动力学模拟在此系统中的应用。并建立链分子的随机混合输运方程，推导聚合物分布函数和扩散率的解析表达，发展在复杂溶液中的细菌的运动简化模型。挖掘更深层次的流体力学与非平衡统计物理规律，并探讨微纳智能器件的设计、控制和应用。

Mixture of self-propelled microorganisms and polymers is ubiquitous in nature and laboratory. The hydrodynamic interaction dominates many properties of the mixture. At present, a lot of experimental observation, numerical simulation and theoretical analysis have been carried out for the mixed system of microorganism and small particles in academia. However, there is still a lack of reliable numerical simulation and theoretical models for more complex polymer systems with internal multi-degree of freedom. In order to reveal the key role of hydrodynamic interaction in structure and dynamics of the mixture, the project will develop numerical simulation method and theory on polymer and self-propelled microorganism. We mainly focus on two key properties of the mixture: 1) morphological transformation and dynamic properties of polymers, including buckling, reversal, migration and diffusion. 2) The movement of self-propelled microorganisms in polymer suspension, including acceleration, deceleration and tumbling. Methodologically, this project intends to develop Stokeslets method and the application of Brownian dynamics simulation with hydrodynamic interaction. We aim to construct kinetic equation about mixing and transport of microorganism and the statistical mechanics of chain molecules and derive the analytical expression of polymer distribution function and diffusivity and develop the simplified model of bacterium swimming in complex suspension. We search for the fundamental fluid mechanics and statistical physics underlying these phenomena. Furthermore, this project will discuss the design, control and application of micro-nano smart devices.