Manganese Oxide-Based Chemically Powered Micromotors.

Chemically powered micromotors represent an exciting research area in nanotechnology. Such artificial devices are typically driven by catalytic bubble formation, taking place at the solid-liquid interface. Platinum has been most frequently used for the fabrication of different micromotors due to its superior catalytic efficiency. Other materials typically suffer from slow speeds and require very high concentrations of chemical fuel. Here, we report preparation and characterization of fast moving micromotors based on manganese oxide (MnO2) with different geometrical shapes (tubes, rods, and spheres). On the basis of the results, the prepared micromotors reached the highest speeds (up to ∼900 μm s(-1) in 10% H2O2) reported to date for any MnO2-based micromotors. Moreover, they moved by bubble propulsion even at very low concentrations of peroxide fuel. Thus, MnO2 represents a promising material for the preparation of micromotors for various biomedical or environmental applications, where high speeds are desired.