Magnetic Helical Micromachines: Fabrication, Controlled Swimming, and Cargo Transport

摘要

Rotation is a fundamental mechanical motion and is crucial for biological and artificial systems at the micro-anoscale. In nature, biomolecular rotary motors drive bacterial flagella and ATP synthase.Inspired by such rotary motors, various micro-anorotors have been developed,including chemical- and light-driven artificial molecular rotors, electric-field-driven DNA nanorotors,chemical-fuel-driven catalytic micro-anorotors, and electric-field-driven CNT-based NEMS. A rotating magnetic field has also been used to rotate a variety of magnetic microano-scale objects, such as single/ self-assembled beads,rigid and flexible wires, and helical structures, in fluid. Among these, helical micro-/ nanoswimmers, inspired by bacterial flagella, convert rotational motion to translational motion, which is one of the well-known propulsion strategies for a low Reynolds number regime.