DESIGN CATALYTIC NANOMOTORS
Yiping Zhao
Department of Physics and Astronomy, University of Georgia , Athens , GA 30602 , USA
Catalytic nanomotors move autonomously by deriving energy directly from their environment mimicking biological nanomotors which are motor proteins that perform a wide range of complex functions at the cellular level and are responsible for the majority of active transport and other movement within cells. They gain mobility by chemical reactions greatly sped-up by onboard catalysts. Recently, researchers have fabricated inorganic catalytic nanomotors with the hope that complex functional machines may one day perform intricate tasks at the cellular and sub-cellular levels. Various design techniques have produced several nanomotor structures including hetero-sectioned Ni/Au nanorotors, Pt/Au nanorod structures, L-shaped and spiral nanomotors, gear-shaped rotary structures, self-propelling plates (macro-scale), spherical nanomotors, and more complex multi-component devises. The control of micro-scale and nano-scale motors is the first step toward designing functional machinery at these scales. Therefore, design focusing upon the type of motion desired is a positive step toward the creation of functional nanomachines. In this study, we implement dynamic shadowing growth (DSG) to fabricate a large number of nearly identical nanomotor structures.
Using a geometric shadowing effect, a thin catalyst layer can be coated asymmetrically on the side of a nanorod backbone. Combining with substrate rotation, a dynamic shadowing growth technique has been developed to fabricate catalytic nanomotors such as rotary Si/Pt nanorods, rotary L-shaped Si/Pt and Si/Ag nanorods, and rolling Si/Ag nanosprings, and their autonomous motions have been demonstrated in a diluted H2O2 solution. This fabrication method reveals an optimistic step toward designing integrated nanomachines.
Nanorod nanomotors
L-shape nanomotors
Rolling of nanospring
Below are some of our papers on nanomotors
J. Gibbs and Y.-P. Zhao, “Catalytic nanomotors,” in “Design of Heterogeneous Catalysts: New Approaches based on Synthesis, Characterization and Modelling” edited by Umit S. Ozkan (Wiley-VCH, 2009), Chap. 6, pp. 141-160.
John G. Gibbs and Yiping Zhao, "Catalytic nanomotors: fabrication, mechanism, and applications," Frontiers of Materials Science, in press.
John G. Gibbs, Nicholas A. Fragnito, and Yiping Zhao, “Asymmetric Pt/Au coated catalytic micromotors fabricated by dynamic shadowing growth,” Appl. Phys. Lett. 97, 253107 (2010).
J. Gibbs and Y.-P. Zhao, "Self-organized multi-constituent catalytic nanomotors," Small 6, 1656–1662 (2010).
J. Gibbs and Y.-P. Zhao, “Design and characterization of rotational multicomponent catalytic nanomotors,” Small 5, 2304-2308 (2009).
J. Gibbs and Y.-P. Zhao, "Autonomously motile catalytic nanomotors by bubble propulsion," Appl. Phys. Lett. 94, 163104 (2009).
J. G. Gibbs and Y.-P. Zhao, “Measurement of driving force of catalytic nanomotors in dilute hydrogen peroxide by torsion balance ,” Rev. Sci. Instrum. 79, 086108 (2008).
J.-X. Fu, Y.-P. Zhao, and J.-S. Wu, “Rotation of Cu nanorods during growth,” J. Phys. Chem. C 112, 5459 - 5462 (2008).
J.-X. Fu, Y.-P. He, and Y.-P. Zhao, “Fabrication of heteronanorod structures by dynamic shadowing growth,” IEEE Sensors 8, 989-997 (2008).
Y. He, J.-S. Wu, and Y.-P. Zhao, "Designin catalytic nanomotors by dynamic shadowing growth," Nano Letters 7, 1369 - 1375 (2007).
