So far, the fabrication and assembly of nano-objects with specific shapes and sizes that can act as elementary components for movable nanoelectromechanical systems (NEMS) is only at the conceptual stage.

New research results coming from South Korea now offer the first step toward the realization of sophisticated nanomachines, designed to perform specific tasks, with overall dimensions comparable to those of biological cells.

"We have fabricated freestanding gold nanogears smaller than 500 nm in overall size and 60-70 nm in thickness and assembled them tooth to tooth without damage" Dr. Dong Han Ha tells Nanowerk. "This is the first case to our knowledge in which freestanding nanocomponents with precisely designed shape and size are fabricated and assembled. The freestanding nanogears with one center hole surrounded by six teeth were obtained reproducibly by selectively etching the chemically synthesized single-crystalline gold nanoplates using gallium focused ion beam (FIB). The fabrication process is very simple and it takes only 10-20 s to fabricate a nanogear under real time monitoring."

Ha is a Principal Researcher in the Division of Advanced Technology at the Korea Research Institute of Standards and Science (KRISS). Together with his colleagues from KRISS he has demonstrate that blunt AFM tips on stiff cantilevers are effective for the nondestructive manipulation of ductile and flat nano-objects having large contact areas with the substrate.

The findings have been reported in the November 20, 2007 online edition of Nanotechnology ("Manipulation of freestanding Au nanogears using an atomic force microscope").