Trimer-like microrobots with multimodal locomotion and reconfigurable capabilities
Shimin Yu, Tianlong Li, Fengtong Ji, Shuqi Zhao, Kai Liu, Zhonglin Zhang, Weiwei Zhang, Yongfeng Mei
Abstract
Despite the growing interest in the motion mechanisms and application potential of individual active colloids/particles in micro/nanorobotics, their aggregation for higher-ordered mesostructures remains a significant challenge due to the complexity of their motion control and dynamics. Here, a magnetic trimer-like microrobot composed of three magnetic Janus colloids with different diameters exhibited multimodal locomotion, frequency-dependent reconfigurability, and contactless manipulation in a 3D environment. Various locomotion modes excited by adjusting the magnetic field rely on different driving principles. At a low Reynolds number, trimer-like microrobots can locomote in a 3D space based on their asymmetric shape distribution and can move on a surface by breaking spatial symmetry. A strategy to reconfigure trimer-like microrobots from β-config to α-config rapidly was implemented by alternating the frequency and strength of the magnetic field. Additionally, the trimer-like microrobots follow a unique chiral rotating mode with self-adjusting capabilities under uniform rotating magnetic field propulsion in horizontal plane. Through the integration of multimodal locomotion, these trimer-like microrobots are capable of moving in complex 3D environments and manipulating passive particles without in-depth contact via fluidic mediation. These trimer-like microrobots can reconfigure their operation mode according to multitasking requirements or in response to environmental variations.