A nanogenerator is a nanoscale (extremely small) device capable of generating electriccurrent, electromagnetic field s or subatomic particle radiation. Several prototypes have been developed that hold promise for use in various fields of anotechnology. Researchers at Georgia Institute of Technology are working on a nanogenerator prototype that uses microscopic wires to generate electricity when they vibrate. The currents arise in zinc-oxide nanowire s as a result of the piezoelectric effect, which is similar to the phenomenon that causes quartz crystals to produce tiny currents when subjected to mechanical stress. The design is in the research-and-development phase. Engineers hope that a working electric nanogenerator will be available by 2010 or 2011. A molecular nanogenerator developed by Memorial Sloan-Kettering Cancer Center causes actinium atoms to release high-speed alpha particles (helium nuclei) that can kill malignant tumor cells. This type of device could have profound implications for medical science, particularly radiology