Swimming microrobots guided in the circulation system offer considerable promise in precision medicine but currently suffer from problems such as limited adhesion to blood vessels, intensive blood flow, and immune system clearance—all reducing the targeted interaction. A swimming microrobot design with clawed geometry, a red blood cell (RBC) membrane–camouflaged surface, and magnetically actuated retention is discussed, allowing better navigation and inspired by the tardigrade’s mechanical claw engagement, coupled to an RBC membrane coating, to minimize blood flow impact. Using clinical intravascular optical coherence tomography in vivo, the microrobots’ activity and dynamics in a rabbit jugular vein was monitored, illustrating very effective magnetic propulsion, even against a flow of ~2.1 cm/s, comparable with rabbit blood flow characteristics. The equivalent friction coefficient with magnetically actuated retention is elevated ~24-fold, compared to magnetic microspheres, achieving active retention at 3.2 cm/s, for >36 hours, showing considerable promise across biomedical applications.

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Highly effective contrast enhancer that processes targeting ability and maneuverability is in great demand in clinics for accurate diagnosis. Here a new strategy using deformable and manipulatable magnetic microswarm as MRI contrast enhancer is developed. Magnetic microswarm aggregated from nanoparticles is inherently deformable and they can be controlled with multiple programmable deform abilities. It is demonstrated that spatiotemporal programming magnetic field enables the magnetic microswarm not only to exhibit both ribbon‐like and round‐like behaviours but also to adaptively navigate multiple terrains. Intestinal model is conducted to explore the effect of magnetic microswarm as MRI enhancer, indicating the obvious enhancement of T2‐weighted MRI sequences. This magnetic microswarm holds great promise for highly sensitive and accurate intestinal MRI in the clinic.

Multimode stimuli-regulated propulsions are extremely useful for artificial micro-/nanomotors in performing specialized tasks in different microscopic environments. However, it is still a great challenge to develop a simple and efficient micro/nanosystem which can operate in complicated environments, either with fuel or without fuel. Here, we report a novel hybrid micromotor which only needs one metal with a special structure: micro-spherical shell with a hole. Since we attractively combine the inherently catalytic properties of Pt for chemical propulsion with a designed concave structure for acoustic propulsion, the micromotors can not only move rapidly in H2O2 fueled environment due to the chemical reaction between Pt and H2O2 but also can exhibit excellent acoustic propulsion in a fuel-free environment due to the non-uniform stress caused by ultrasound. In addition, the attractive group motion behavior of the motors, including aggregation, group migration, and dispersion, is easily realized by acoustic field regulation. The brand-new single-metal hybrid micromotors with a dual driving mode, flexible propulsion regulation, and efficient group motion regulation, which are essential for making micro-/nanomotors compatible with different surrounding environments, are expected to advance the field of artificial nanomachines.