CATALYTIC NANOMOTORS
The fabrication of integrated nanomachinary systems can enable break-through applications in nanoelectronics, photonics, bioengineering, and drug delivery or disease treatment. Naturally occurring nanomotors are biological motor proteins powered by catalytic reactions, which converts the chemical energy into mechanical energy directly. It has been demonstrated recently that using a simple catalytic reaction and an asymmetric bimetallic nanorod, one can produce catalytic nanomotors that mimic the autonomous motions of bionanomotors. Yet the construction of artificial nanomachines remains a major contemporary challenge due to the lack of a flexible fabrication technique that can design the desired dynamic components. We use a design technique called dynamic shadowing growth that allows for the fabrication of a wide range of various geometries and the asymmetric placement of the catalyst is easily accomplished as well. Programming nanomotor behavior is possible through geometrically-focused design and by incorporating different materials into the nanomotor structure. A propulsion mechanism based upon bubble ejection from the catalyst surface is introduced to explain the driving force as well. We have also successfully incorporated multiple parts to form complex nanomotor assemblies which exhibit motions not observed from individual parts.
