Flexible self-forming swimmers with catalytic propulsion and magnetic navigation

We report on an inexpensive rapid process for creating soft, mm-scale, self-forming catalytic swimmers for potential biomedical and environmental applications. The swimmers contain a catalyst that upon exposure to H
₂
O
₂
result in bubble formation and self-propulsion. With the additional incorporation of ferrofluid (a suspension of iron oxide nanoparticles), we control the navigation of the swimmers using a magnetic field. Fabrication uses techniques which are scalable, economical, and adaptable for large-volume manufacturing (e.g., roll-to-roll). The devices are created using a planar design that upon immersion in an aqueous environment fold up to create a 3D structures (tapered cylinder). A maximum swimming speed of 7.2 mm/s is observed using 20 % H
₂
O
₂
.