Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany.
Institute for Biomedical Engineering, ETH Zurich, Zurich, 8092, Switzerland.
Small. 2023 Nov;19(47):e2303396. doi: 10.1002/smll.202303396. Epub 2023 Jul 24.
Controlled microrobotic navigation inside the body possesses significant potential for various biomedical engineering applications. Successful application requires considering imaging, control, and biocompatibility. Interaction with biological environments is also a crucial factor in ensuring safe application, but can also pose counterintuitive hydrodynamic barriers, limiting the use of microrobots. Surface rolling microrobots or surface microrollers is a robust microrobotic platform with significant potential for various applications; however, conventional spherical microrollers have limited locomotion ability over biological surfaces due to microtopography effects resulting from cell microtopography in the size range of 2-5 µm. Here, the impact of the microtopography effect on spherical microrollers of different sizes (5, 10, 25, and 50 µm) is investigated using computational fluid dynamics simulations and experiments. Simulations revealed that the microtopography effect becomes insignificant for increasing microroller sizes, such as 50 µm. Moreover, it is demonstrated that 50 µm microrollers exhibited smooth locomotion ability on in vitro cell layers and inside blood vessels of a chicken embryo model. These findings offer rational design principles for surface microrollers for their potential practical biomedical applications.
在体内进行受控的微型机器人导航在各种生物医学工程应用中具有重要的潜力。成功的应用需要考虑成像、控制和生物相容性。与生物环境的相互作用也是确保安全应用的关键因素，但也会带来反直觉的流体动力障碍，限制了微型机器人的使用。表面滚动微型机器人或表面微滚轮是一种强大的微型机器人平台，具有广泛的应用潜力；然而，由于细胞微形貌在 2-5 µm 范围内的微形貌效应，传统的球形微滚轮在生物表面上的移动能力有限。在这里，使用计算流体动力学模拟和实验研究了不同尺寸（5、10、25 和 50 µm）的球形微滚轮的微形貌效应的影响。模拟结果表明，随着微滚轮尺寸的增加，微形貌效应变得不显著，例如 50 µm。此外，研究表明 50 µm 微滚轮在体外细胞层和鸡胚模型的血管内表现出平滑的运动能力。这些发现为表面微滚轮的潜在实际生物医学应用提供了合理的设计原则。
