A microvehicle with iron wheels (gold) and a polymer chassis (red). (Credit: Alcântara et al. Nature Communications 2020)

Using a new manufacturing technique, scientists have built microrobots out of metal and plastic, in which these two materials are interlocked as closely as links in a chain. The high-precision 3D printing technique produces complex objects on the micron level, a technique known as 3D lithography. The scientists produced a kind of mold or template for their micromachines. These templates have narrow grooves that serve as a negative and can be filled with the chosen materials. They filled some of the grooves with metal and others with polymers before ultimately dissolving the template away with solvents.

As a proof of principle, the scientists created various miniscule vehicles with plastic chassis and magnetic metal wheels powered by means of a rotating magnetic field. Some of the vehicles can be propelled across a glass surface, while others — depending on the polymer used — can float in liquid or on a liquid surface. They plan to refine their two-component micromachines and experiment with other materials. In addition, they will attempt to create more complex shapes and machines, including some that can fold and unfold themselves.

For more information, visit here .