关键词: 磁性液滴, 液滴生成, 过程控制, 动力学模型

Abstract: In recent years, magnetic droplets with microscale, multiphase and contactless properties have received wide attentions from researcher of science and business for their successful applications in biological cell separation and targeted drug therapy. However, the main challenge is how to manipulate magnetic droplets approaching the set position accuracy. Therefore, three aspects including the current methods of generating and manipulating magnetic droplets, the basic mechanism of magnetic droplet manipulation and their control mechanism were summarized in this work. At present, the control methods for magnetic droplets can be divided into three categories. The first type was the permanent magnets-mechanical method where permanent magnets were placed on a mechanically mobile platform. By means of moving the platform, the distance between the permanent magnet and the microchip was changed and then the magnetic field intensity was also regulated. Moreover, the dynamic magnetic droplets were controlled. The second type was the electromagnet-electric method where the situation errors of droplets were detected by high-speed camera and sent to controller and the prebuilding mathematical model to obtain control output in order to regulate magnetic field intensity for manipulates the magnetic droplet. The third type was permanent magnets/electromagnet-electric mixed method where advantages of two methods mentioned above were combined to manipulate magnetic droplets for better control. Finally, the drawbacks and difficulties of current methods of magnetic droplets generating and manipulating were summarized and further possible research techniques and research fields were prospected.

Key words: magnetic droplets, droplet generation, process control, dynamics model