Front Cover: Reversible Speed Regulation of Self‐Propelled Janus Micromotors via Thermoresponsive Bottle‐Brush Polymers (Chem. Eur. J. 10/2021).

Manganese ions are embedded in microporous silica nanoparticles to catalyse the degradation of the H SB 2 sb O SB 2 sb "fuel" to water and gaseous oxygen. Keywords: bottle-brush polymers; mesoporous silica; micromotors; microparticles; polyphosphazenes EN bottle-brush polymers mesoporous silica micromotors microparticles polyphosphazenes 3187 3187 1 02/17/21 20210215 NES 210215 B Self-propelled micromotors b with a reversible braking system are shown. Manganese ions are embedded in microporous silica nanoparticles to catalyse the degradation of the H SB 2 sb O SB 2 sb "fuel" to water and gaseous oxygen. [Extracted from the article]