Fig. 13.

(A) Illustration of enzymatic micropumps. Reproduced with permission from ref 128. Copyright 2014, Nature. (B) The fabrication of functional silk stirrers using reactive inkjet printing, the rotation center of dual-engine and single-engine silk stirrers during stirring action, still video frames from catalase propelled single-engine stirrers and dual-engine stirrer in the presence of H₂O₂ solutions. Reproduced with permission from ref 131. Copyright 2018, Wiley. (C) Removal of phenolic pollutants by dual-function plant (radish) motors. Reproduced with permission from ref 41. Copyright 2014, Royal Society of Chemistry. (D) Trajectories (inset) and corresponding MSD plot of lipase-powered nanomotors at different triacetin concentrations, the color change of the surrounding litmus solution along time indicates the generation of butyric acid(scale bar: 5 μm), degradation percentage of tributyrin droplets by lipase powered motors at different times. Reproduced with permission from ref 50. Copyright 2019, Wiley.