磁性微型机器人及群的大空间自主导航研究

磁性微型机器人被广泛应用于靶向治疗，但是磁性微型机器人在制备、自主导航、群体控制以及残余物回收等方面仍有不足。为了使微型机器人能够在狭窄通道中运动，需要实现尺寸和形状可控地制备磁性微型机器人。由于磁性微型机器人在多障碍物的环境下运动，需要结合人工智能技术实现磁性微型机器人在复杂的非结构化环境下自主导航，同时磁性微型机器人还需要具备长距离运动的能力以满足实际应用要求。鉴于单个磁性微型机器人存在个体小难以显微成像以及药物负载量低的缺陷，实现群体的自主导航可以进一步提高磁性微型机器人的靶向效率。本文针对以上问题研究了具有生物可降解性的磁性微型机器人尺寸形状 可控地制备，磁性微型机器人以及群在大空间下的自主导航。

本文使用离心微流道的方法制备可生物降解的磁性海藻酸钙微型机器人，并且利用 COMSOL 建立微型机器人制备的物理模型。通过仿真和实验相互验证，本文总结针头与液面距离，溶液浓度以及离心机转速三个因素对微型机器人尺寸和成形性的影响，实现尺寸以及形状可控地制备微型机器人。

针对微型机器人在显微环境中存在视野范围和成像分辨率之间的矛盾，本文提出了基于图像拼接覆盖多个视场的全局地图的获取，并基于全局图像进行全局规划以及局部路径提取，结合 PD 控制器以及位移平台的控制，使微型机器人能够实现大空间的自主导航，这极大地扩展了微型机器人的工作空间。

本文对微型机器人群的形成以及运动进行了研究，并且实现了群在非结构化环境下的大空间自主导航，群的模态切换提高了群对环境的适应性。群的大空间自主导航进一步提高微型机器人的靶向效率。

最后，结合上述技术实现了负载有药物的微型机器人的靶向药物递送，在到达靶向位置之后将微型机器人降解使药物释放，并将残余的磁性纳米颗粒利用群的自主导航策略进行回收，大大提升了对残余的磁性纳米颗粒的回收效率。

本文旨在拓展微型机器人的工作空间进而提高微型机器人的靶向性，并减少 微型机器人的残留。尺寸以及形状可控地制备了具有生物可降解性的微型机器人， 利用大空间自主导航策略提高了微型机器人以及群的靶向性，并且利用微型机器 人的可降解性和群的自主导航实现了对残余的磁性纳米颗粒的回收。

Magnetic microrobots have been widely used in targeted therapy, but there are still challenges in preparation, autonomous navigation, swarm control, and retrieving magnetic nanoparticles. To enable microrobots to move through narrow channels, it is necessary to achieve size and shape controllable preparation of magnetic microrobots. Since magnetic microrobots move in environments with multiple obstacles, they need to be combined with artificial intelligence technology to achieve autonomous navigation in complex unstructured environments. At the same time, magnetic microrobots also need to have the ability to move long distances to meet practical application requirements. In view of the shortcomings of a single magnetic microrobot, which is difficult to perform microscopic imaging and has a low drug load, realizing autonomous navigation of a group can further improve the targeting efficiency of magnetic microrobots. In view of the above problems, this research studies the preparation of biodegradable magnetic microrobots with controllable size and shape, magnetic microrobots, and the autonomous navigation of swarm in a large space.

This research used the centrifugal microfluidic method to prepare magnetic calcium alginate microrobots, and established a physical model of microrobot preparation with COMSOL. Through mutual verification of simulation and experiment, this research summarized the influence of three factors: the distance between the needle and the liquid surface, the solution concentration, and the centrifuge speed on the size and formability of the microrobot, and finally achieved the preparation of microrobots with controllable size and shape.

In view of the contradiction between the field of view and imaging resolution of microrobots in the microscopic environment, this research proposed the acquisition of a global map covering multiple fields of view based on image stitching and performs global planning and local path extraction based on the global image, combined with The movement of the PD controller and the displacement platform enabled the microrobots to realize autonomous navigation in a large space, which greatly expanded the workspace of the microrobot.

This research studied the formation and movement of swarm, and realized the large space autonomous navigation of the swarm in an unstructured environment. The mode II Abstract switching of the swarm improved the swarm’s adaptability to the environment. The large space autonomous navigation of the swarm further improved the drug-carrying efficiency of microrobots.

Finally, combined with the above technology, targeted drug delivery of drug-loaded microrobots was achieved. After reaching the target location, the microrobots were degraded to release the drug, and the remaining magnetic nanoparticles were recovered using the autonomous navigation strategy of the swarm. The strategy of using swarms for recycling greatly improves the recovery efficiency of residual magnetic nanoparticles. This research aims to expand the working space of microrobots, thereby improving the targeting of microrobots and reducing the residue of microrobots. Biodegradable microrobots were prepared with controllable size and shape. The large-space autonomous navigation strategy was used to improve the targeting of microrobots and swarms. The degradability of microrobots and the autonomous navigation of swarms were used to retrieve magnetic nanoparticles.

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