This invention presents a novel method to form uniform or heterogeneous, straight or curved and size-controllable nanostructures including, for example, nanotubes, nanowires, nanoribbons, and nanotapes, including SiNW, using a nanochannel template. In the case of semiconductor nanowires, doping can be included during growth. Electrode contacts are present as needed and may be built in to the template structure. Thus completed devices such as diodes, transistors, solar cells, sensors, and transducers are fabricated, contacted, and arrayed as nanowire or nanotape fabrication is completed. Optionally, the template is not removed and may become part of the structure. Nanodevices such as nanotweezers, nanocantilevers, and nanobridges are formed utilizing the processes of the invention.