A variety of devices at nanometer/molecular scale for electronic, photonic, optoelectronic, biological, and mechanical applications have been created through the rapid development of materials and fabrication technology. Further development of nanodevices strongly depends on the state-of-the-art knowledge of science and technology at the sub-100 nm scale. This book presents and highlights some of the key advances on, but not limited to, electronic and optoelectronic devices of nanometer/molecular scale, nanomechanics and nanoelectromechanical systems, electromechanical coupled devices, manipulation and aligning processes at nanometer/molecular scale, quantum phenomena, modeling of nanodevices and nanostructures, fabrication and property characterization of nanodevices, and nanofabrication with focused beam technology.