A relatively thick electrode is positioned opposite the surface of a substrate/second electrode. The electrode and the substrate surface are both contacted by a solution including silicon nanoparticles. The substrate surface is completely immersed in the solution in a manner such that there is not an air/solution interface and there is no meniscus at the substrate surface. Application of electrical potential between the electrode and the substrate creates a film of silicon nanoparticles on the substrate. Drying of the film induces the film to roll up and form a silicon nanoparticle nanotube material. A film may be subdivided into an array of identical portions, and the identical portions will roll into identical tubes having same length and diameter. A silicon nanoparticle nanotube material of the invention includes nanotubes formed of silicon nanoparticles.