In narrow, unstructured underwater environments such as environmental monitoring and minimally invasive medical procedures, micro soft robots exhibit unique advantages due to their flexible movement capabilities and small size. At the same time, applying bionic technology to the structural design of micro soft robots can significantly improve their swimming performance. However, limited by their miniaturization, these robots are difficult to power internally and usually adopt a wireless power supply method. This study designs and fabricates a magnetically responsive, cownose ray-inspired micro soft robot based on the swimming principle of the cownose ray. The robot is made of a certain proportion of NdFeB and PDMS. Then, a three-dimensional Helmholtz coil is used to generate an oscillating harmonic magnetic field to conduct swimming experiments on the robot, exploring the influence of magnetic field parameters on the robot's swimming performance. The experimental results show that the swimming speed is the fastest at B = 5 mT and f = 11 Hz, reaching 5.25 mm/s, which is about 0.5 body lengths per second. In addition, by adjusting the current direction and frequency of the coil, the robot can perform different swimming modes such as straight swimming, turning swimming, and directional swimming. By employing a stepwise adjustment method, the impact of response errors on the robot's trajectory can be effectively reduced. This study demonstrates a method for magnetically driven micro soft robots, laying a foundation for the application of wireless-driven robots in underwater narrow spaces.

翻译：在环境监测、微创医疗等狭窄非结构化的水下环境中，微型软体机器人凭借其灵活的运动能力和小型化尺寸展现出独特优势。同时，将仿生技术应用于微型软体机器人的结构设计可显著提升其游动性能。然而受限于微型化，这类机器人难以内置供能装置，通常采用无线供能方式。本研究基于牛鼻鲼的游动原理，设计并制备了一种磁响应仿牛鼻鲼微型软体机器人。该机器人由特定比例的钕铁硼与聚二甲基硅氧烷复合制成。随后利用三维亥姆霍兹线圈产生振荡谐波磁场，对机器人进行游动实验，探究磁场参数对机器人游动性能的影响。实验结果表明，在B=5 mT、f=11 Hz时游动速度最快，可达5.25 mm/s，约合每秒0.5倍体长。此外，通过调节线圈电流方向与频率，机器人可实现直线游动、转向游动、定向游动等不同运动模式。采用分步调节方法可有效降低响应误差对机器人运动轨迹的影响。本研究展示了一种磁驱动微型软体机器人的实现方法，为无线驱动机器人在水下狭窄空间的应用奠定了基础。