多重推进式鞭毛泳动磁微机器人系统研究

发布时间：2018-11-07 10:07

【摘要】：微机器人在生物医学工程和微纳制造如靶向药物传递、显微外科手术和微纳操作等领域发挥着越来越重要的作用,具有巨大的发展潜力。鞭毛微机器人相对于螺旋结构的微机器人,具有结构简单和柔顺性好的优点。但目前现有的鞭毛磁微机器人驱动方式单一,通常只能通过单种推进方式驱动,因而环境适应性差。由于生物医学和微纳制造等领域中微机器人的工作环境复杂多变,因此研究具有较强环境适应性的多重推进式微机器人具有重要意义。本文提出一种多重推进式鞭毛泳动磁微机器人,能够分别在磁梯度场、旋转磁场和摆动磁场下驱动前进。分别建立磁微机器人在液体环境中三种磁推进方式下的动力学模型,并在建立适用多重推进式线圈磁驱动系统的基础上,提出微机器人的控制策略,开展多重推进式鞭毛泳动磁微机器人的实验研究。首先,提出一种多重推进式鞭毛泳动磁微机器人的结构。根据液体环境中流体阻力理论,结合磁场特性,分别建立鞭毛泳动磁微机器人在磁梯度场、旋转磁场和摆动磁场下的动力学模型。在此基础上,分析鞭毛外形尺寸、弹性模量、鞭毛倾斜角度等参数对微机器人的运动速度以及能量转化效率的影响规律。并通过仿真获取鞭毛在不同磁场驱动下的变形规律。其次,依据多重推进式鞭毛泳动磁微机器人的特征,构建适于此类磁微机器人的驱动模块。基于亥姆霍兹线圈驱动系统,增加有效的转换模块,使传统的亥姆霍兹线圈亦能产生梯度磁场,以满足磁微机器人多重推进需求。分析比较各种磁场的产生方式,并利用多物理场仿真COMSOL软件,仿真获得磁场的分布特性。依据仿真结果,编制对应的控制程序,用以分别产生磁梯度场、旋转磁场和摆动磁场,并通过实验测试磁场的真实情况。最后,开展多重推进式鞭毛泳动磁微机器人的实验研究。基于之前建立的驱动系统,制作多种参数的多重推进式磁微机器人,并开展不同尺寸参数下的微机器人在各种磁场驱动下的实验研究。通过实验获得的关于微机器人的相关性能结果,并将其与理论计算结果相比较。实验结果表明,多重推进式鞭毛泳动磁微机器人在旋转磁场或摆动磁场的驱动下,更适用于在粘性较高的甘油等液体中运动,而在磁梯度场的驱动下,更适用于在粘性比较低的液体中运动。在粘性多变的复杂液体环境中,本文提出的多重推进式鞭毛泳动磁微机器人适应能力更强。
[Abstract]:Microrobots play a more and more important role in biomedical engineering and micro-nano manufacturing such as targeted drug delivery, microsurgery and micro-nano operation, and have great potential for development. Compared with spiral micro robot, flagellum micro robot has the advantages of simple structure and good flexibility. However, the current flagellum magnetic microrobot drive mode is single, usually can only be driven by a single propulsion mode, so the environmental adaptability is poor. Because of the complex and changeable working environment of micro-robot in biomedical and micro-nano manufacturing fields, it is of great significance to study multi-propulsion micro-robot with strong environmental adaptability. In this paper, a multi-push flagellated swimming microrobot is proposed, which can be driven forward by magnetic gradient field, rotating magnetic field and oscillating magnetic field, respectively. The dynamic models of magnetic microrobot under three kinds of magnetic propulsion modes in liquid environment are established, and the control strategy of the micro robot is proposed on the basis of establishing a magnetic drive system suitable for multiple propulsion coils. The experimental study of multi-push flagellum swimming-magnetic micro-robot was carried out. Firstly, a multi-push micro-robot for flagellating swimming is proposed. Based on the theory of fluid resistance in liquid environment and the characteristics of magnetic field, the dynamic models of flagellated swimming magnetic microrobot under magnetic gradient field, rotating magnetic field and oscillating magnetic field are established respectively. On this basis, the effects of parameters such as flagellum shape size, elastic modulus and flagellum inclination angle on the motion speed and energy conversion efficiency of the micro robot are analyzed. The deformation law of flagella driven by different magnetic fields was obtained by simulation. Secondly, according to the characteristics of multi-push flagellated swimming microrobot, a driving module is constructed for this kind of microrobot. Based on the Helmholtz coil drive system, an effective conversion module is added, so that the traditional Helmholtz coil can also produce gradient magnetic field to meet the need of multiple propulsion of the magnetic micro-robot. The generation methods of magnetic field are analyzed and compared, and the distribution characteristics of magnetic field are obtained by using the COMSOL software of multi-physical field simulation. According to the simulation results, a corresponding control program is developed to generate magnetic gradient field, rotating magnetic field and oscillating magnetic field respectively, and the real situation of the magnetic field is tested by experiments. Finally, the experimental study of multi-push flagellum swimming micro-robot is carried out. Based on the previously established drive system, the multi-push magnetic microrobot with various parameters is fabricated, and the experimental study of the micro-robot driven by various magnetic fields with different parameters is carried out. The experimental results about the correlation energy of the micro robot are compared with the theoretical results. The experimental results show that, driven by rotating magnetic field or swinging magnetic field, multi-push flagellated swimming microrobot is more suitable for moving in glycerol with higher viscosity, but driven by magnetic gradient field. It is more suitable for moving in liquid with lower viscosity. In the complex liquid environment with variable viscosity, the multi-push flagellated swimming magnetic micro robot proposed in this paper has better adaptability.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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