  With recent developments in nanotechnology, self-assembled structures are
providing convenient, cheaper and more precise ways of manufacturing various
patterns and shapes with less complexity. Of these self-assembled structures,
rolled-up nano-tubes play a vital role in various aspects. The notion is, the
utilization of strain energy developed during epitaxial growth of a bilayer
thin film over a substrate, mediated by a sacrificial layer. While the
sacrificial layer is etched, the bilayer film is subjected to release its own
in-built strain energy in the out-of-plane direction (3D structure) due to a
bending stress induced by biaxial strain through the thickness, in the bilayer.
This paper proposes a new method of fabricating conical self-rolled assembly by
thickness and strain variations along the width of the bilayer and, cylindrical
structure of variable radius due to thickness and strain variations along the
length.
