Nanostructured Origami (TM) : folding thin films out of the plane of a silicon wafer with highly stressed chromium hinges

Abstract

This thesis addresses the construction of complex three-dimensional (3-D) nanostructures using only 2-D, planar nano-fabrication techniques. In the state of the art, multiple 2-D layers are fabricated in series, each directly on top of the previous. The method advocated here is Nanostructured Origami, in which multiple adjacent 2-D layers are fabricated in parallel and are then folded into the desired 3-D configuration using the appropriate folding sequence. This thesis focuses on folding actuation for this method using the residual tensile stress in vacuum-evaporated chromium to fold silicon nitride membranes. Our results conclusively demonstrate the ability to pattern these membranes with nano-scale features and then controllably fold them into a predetermined 3-D configuration. Future work will refine the fabrication procedure for large-scale manufacturing and address alignment and latching of the folded membranes.