柔性仿生磁性微结构的制备与驱动

根据自然界中一些在黏性介质中游动的生物的运动原理,制备了一种由磁性头部和无磁性尾部构成的柔性仿生微结构,可通过均匀振荡磁场驱动。结合振荡磁场的产生原理建立运动学模型,以分析磁性微结构在振荡磁场驱动下的振荡特性。在驱动过程中分别设置磁场的振荡角为60°、90°和120°,微结构的游动速度随着磁场振荡角的增大而增加。通过研究微结构在驱动过程中的频率响应,确定了微结构在振荡角为60°、失步频率为15 Hz时,获得的最大游动速度为105μm/s,而当振荡角为90°和120°、失步频率为25 Hz时,获得的最大游动速度分别为117和179μm/s。低于失步频率时,游动速度随着频率的增加而增大,但是高于失步频率后,游动速度随之降低。结合微结构的振荡模型,分析了失步的原因,并论证了微结构的振荡角和振荡频率在频率响应中的作用机制。

Fabrication and Actuation of the Flexible Biomimetic Magnetic Microstructure

According to the movement principle of some creatures swimming in the viscous media in nature,a flexible biomimetic microstructure with the magnetic head and non-magnetic tail was fabricated,and could be actuated by the uniform oscillating magnetic field.Combined the generation principle of the oscillating magnetic field,a kinematic model was established to analyze the oscillating characteristics of the magnetic microstructure actuated by the oscillating magnetic field.In the actuation process,the oscillation angles of the magnetic field were set to 60°,90°and 120°,respectively.And the swimming speed of the microstructure increases with the increase of the magnetic oscillation angle.By studying the frequency response of the microstructure in the actuation process,it is determined that at the oscillation angle of 60°and the step-out frequency of 15 Hz,the maximum swimming speed of the microstructure is 105μm/s,and at the oscillation angles of 90° and 120° and the step-out frequency of 25 Hz,the maximum swimming speeds of the microstructure are 117 and 179μm/s,respectively.And below the step-out frequency,the swimming speed increases as the frequency increases,while above the step-out frequency,the swimming speed decreases as the frequency increases.Combined the oscillation model of the microstructure,the cause of the step-out was analyzed,and the mechanisms of the oscillation angle and oscillation frequency of the microstructure in the frequency response were demonstrated.