活化复杂环境中自驱动人工马达的设计和动力学性质研究

Synthetic micro/nano motors have wide potential applications in drug delivery, bio-sensing, nanoscale self-assembly, and so on. Since the man-made motors are powered by catalytic reaction from surrounding environment, it is essential to study the influences of active environment on the dynamical of motors. Previous investigations mostly are carried out in homogeneous systems. Given the environment of motor is chemical active and in a non-equilibrium state, it greatly affects the dynamical behavior of the motor. However, it is far from being understood about its physical mechanism describing interactions among multiple-fields and many-bodies at the present stage. Therefore, it attracted considerable interest in recent studies. In this research proposal, we will investigate the design and dynamics behavior of motor in active environment. In addition to theoretical analysis, a particle-based mesoscopic simulation method is utilized. The main content includes:1) Making use of spatial-temporal patterns (such as Turing pattern, Faraday pattern, spiral wave, etc.) to control the motion of nanomotor, and studying the dynamical behavior of nanomotor in Oscillatory and Bi-stable system ；2）Studying the mechanism to design intelligent motor which can carry out the tasks including target delivery, capture, and chemotactic behavior; 3)investigating the dynamical behavior in a flow environment, pattern-based assembly, and control of collective structure by reversible reaction. We believe the studies can contribute to the understanding of motor dynamics in complex active environment, and enrich the mechanisms on how to design an efficient self-propelled motor. It will shed light on the fabrication of motors in Lab.

微/纳米尺度的人工马达，在药物靶向输运、生物传感、自组装等多方面具有广阔的应用前景。由于环境提供“自驱动能量”，其对马达动力学的影响已成为核心科学问题。已有的研究多在均匀环境中开展，然而马达实际环境是化学活化的非平衡态体系，显然其影响要复杂、丰富的多，但迄今为止，仍缺少对此重要影响的深入研究，尤其对其多场、多体耦合的物理机制仍然不甚清晰。本项目采用新的介观模拟技术，在粒子水平构建活化斑图环境，从理论上探索新的驱动机制和智能控制设计，主要内容有：1)在不同时空特性的活化环境中，调控马达运动，并提出新的驱动机理；2)研究具有靶向输运和生物传感等智能的自驱动马达的设计机理；3)研究斑图为衬底的马达自组装、反应调控的马达集体结构、流场下马达集体行为等多体动力学性质。本项目有助于解决活化环境中马达动力学驱动机制这一非平衡态统计物理前沿问题，从而丰富马达的设计机理，为实验及诸多潜在应用提供理论基础。

经过4年工作的开展,本项目基本完成了预设的研究目标.首先, 较为系统地揭示了化学能驱动的微纳米马达间如何通过化学协作展示丰富的动力学性质。给出了各种条件下双面胶球粒子周围流场的丰富形式;发现了钉扎的双面胶球依赖于化学梯度场的关联构型,并得出马达在细丝(细胞骨架)网络上的动力学性质及网络的响应特性.接着,从微马达实际应用环境出发，利用时空斑图为燃料，通过抑制马达的随机布朗旋转，达到引导微马达沿着预先设计的路线运动的控制目标，提供了一种应用环境驱动和控制微马达定向长程输运的途径。并以斑图为衬底自组装形成各类有序微结构，发展了一种新的受限自组装方法。然后,提出了一种可利用化学和物理双重性质筛选纳米颗粒的新策略,克服了传统方法难以筛选具有相似物理性质纳米颗粒的缺陷.化学振荡环境影响马达的梯度场.研究发现马达集体在振荡过程中展示了分散-聚集的动力学转变,并伴随着不同标度率的扩散行为.对于配对马达,通过构造极限环振荡环境,发现了配对的多种构型,并给出了相图.此外,项目还研究了自驱动转子马达的集体动力学,发现转子马达形成旋转的配对构型,并得出马达的手征性引起配对构型的形成机理.最后,项目研究了自驱动马达在细丝上的运动特性,发现细丝网络的结构和结合力影响马达的集体行为,特别是马达在连接处能够形成强的团簇.. 项目取得了一些创新结果,共计发表SCI/EI论文11篇,其中IF大于15论文2篇,主封面论文1篇(Nanoscale),获省部级奖励1项.主办和参与协办全国和地区学术研讨会4次.