Abstract：PPy—COOH/PPy/Ni/Pt multilayer tubular micromotors were fabricated by using template-assisted electrochemical deposition method. The amount of deposition charge and the concentration of pyrrole for the deposition of PPy layer were optimized. The results show that the optimal amount of deposition charge is 0.5 C and the optimal concentration of pyrrole is 74 mmol/L. Scan electron microscope (SEM) , energy dispersive X-ray spectroscopy (EDS) , 3, 3', 5, 5'-tetramethylbenzidine-horseradish peroxidase (TMB-HRP) -based colorimetric method and optical microscope were used to characterize the structure, component and motion behavior of the as-obtained tubular micromotors. SEM images shows that the obtained tubular micromotors were dominated by uniform single cone-shaped structures with smooth outer layer and rough inner layer. EDX mapping analyses clearly reveals the existence of C, N, Ni and Pt within the tubular micromotors. The result of TMB-HRP-based colorimetric method indicates the presence of carboxyl groups on the outer surface of the tubular micromotors.Motion behavior analyses shows the speed of the tubular micromotors can be enhanced effectively with the increase of the fuel concentration. When the concentration of H2 O2 was 4%, the speed of tubular micromotors can be increased to 485 μm/s. In addition, the result also shows that the motion of micromotors can be controlled by an external magnetic field.

Keywords： tubular micromotors; self-propulsion; electrochemical deposition