Researchers at Eindhoven University of Technology in the Netherlands have created artificial cilia that move like a wave when introduced to a rotating magnetic field with potential applications for for soft robotics and microfluidic pumps.

Mimicking actual cilia — which are microscopic hair-like vibrating structures found on the surface of certain cells that cause currents in the surrounding fluid, or found in protozoans and other small organisms, providing propulsion — the researchers injected a polymer with carbonyl iron powder particles and poured the substance into identical cylindrical holes.

The cilia-propelled micro-robot (middle), with a close-up of its cilia at top. Source: American Chemical Society

As the polymer cured, the researchers put magnets under the molds to alter the alignment of the particles as well as the magnetic properties in nearby cilia. The ability of artificial cilia to move in water and glycerol was demonstrated when a rotating magnetic field was applied. According to the team, while the magnets moved around the array, the cilia quickly moved back and forth, thereby generating a flow that was faster than previously achieved using other artificial cilia.

The researchers believe that the artificial silica could be used to create microfluidic pumps and soft robots for biomedical applications. For more on the research, watch the accompanying video that appears courtesy of the American Chemical Society.

The research — Metachronal μ-Cilia for On-Chip Integrated Pumps and Climbing Robots — also appears in the journal ACS Applied Materials and Interfaces.