Magnetically actuated miniature walking soft robot based on chained magnetic microparticles-embedded elastomer

[Display omitted] •A chained magnetic microparticles-embedded elastomer based magnetically actuated miniature walking soft robot was developed.•Magnetic elastomer exhibited repeated bending and flattening under alternating magnetic field.•Our soft robot demonstrated high velocity (∼2.7 mm/s), which is higher than conventional soft robots with similar dimension. Untethered miniature robots have attracted attention in biomedical fields because it could enable various in vivo applications, such as delivering stem cells or tissue sampling from the conventionally inaccessible locations. However, the average velocity of existing soft polymer-based miniature robot remains inefficient for practical application. Here, we developed a chained magnetic microparticles-embedded elastomer based magnetically actuated miniature walking soft robot with a high average velocity (∼ 2.7 mm/s), which is higher than conventional soft polymer-based robots with similar dimension. To maximize average velocity, we optimized magnetization of the robot by controlling the alignment of the magnetic microparticles. We also introduced “legs” on the miniature robot to efficiently convert transversal motion to longitudinal motion. Also, the robot poses high reversible stretchability (∼ 845 %). We expect that the proposed soft robot will enable various biomedical applications, which requires high velocity