Gao Qian, Lin Tingting, Liu Ziteng, Chen Zebiao, Chen Zidong, Hu Cheng, Shen Teng
Luohe Institute of Technology, Henan University of Technology, No. 123, University Road, Yuanhui District, Luohe 462000, China.
Higher Education Mega Center, Guangzhou University, No. 230, West Waihuan Street, Guangzhou 510006, China.
Micromachines (Basel). 2024 May 31;15(6):731. doi: 10.3390/mi15060731.
Magnetic soft microrobots have a wide range of applications in targeted drug therapy, cell manipulation, and other aspects. Currently, the research on magnetic soft microrobots is still in the exploratory stage, and most of the research focuses on a single helical structure, which has limited space to perform drug-carrying tasks efficiently and cannot satisfy specific medical goals in terms of propulsion speed. Therefore, balancing the motion speed and drug-carrying performance is a current challenge to overcome. In this paper, a magnetically controlled cone-helix soft microrobot structure with a drug-carrying function is proposed, its helical propulsion mechanism is deduced, a dynamical model is constructed, and the microrobot structure is prepared using femtosecond laser two-photon polymerization three-dimensional printing technology for magnetic drive control experiments. The results show that under the premise of ensuring sufficient drug-carrying space, the microrobot structure proposed in this paper can realize helical propulsion quickly and stably, and the speed of motion increases with increases in the frequency of the rotating magnetic field. The microrobot with a larger cavity diameter and a larger helical pitch exhibits faster rotary advancement speed, while the microrobot with a smaller helical height and a smaller helical cone angle outperforms other structures with the same feature sizes. The microrobot with a cone angle of 0.2 rad, a helical pitch of 100 µm, a helical height of 220 µm, and a cavity diameter of 80 µm achieves a maximum longitudinal motion speed of 390 µm/s.
磁性软微机器人在靶向药物治疗、细胞操控等方面有着广泛应用。目前，磁性软微机器人的研究仍处于探索阶段，且大部分研究集中在单一螺旋结构上，这种结构在高效执行载药任务方面空间有限，在推进速度方面无法满足特定医学目标。因此，平衡运动速度和载药性能是当前需要克服的一项挑战。本文提出了一种具有载药功能的磁控锥螺旋软微机器人结构，推导了其螺旋推进机制，构建了动力学模型，并采用飞秒激光双光子聚合三维打印技术制备了微机器人结构用于磁驱动控制实验。结果表明，在确保有足够载药空间的前提下，本文提出的微机器人结构能够快速、稳定地实现螺旋推进，且运动速度随着旋转磁场频率的增加而提高。腔径较大且螺旋节距较大的微机器人表现出更快的旋转前进速度，而螺旋高度较小且螺旋锥角较小的微机器人在相同特征尺寸的其他结构中表现更优。锥角为0.2弧度、螺旋节距为100微米、螺旋高度为220微米且腔径为80微米的微机器人实现了390微米/秒的最大纵向运动速度。
