Nanostructured Origami Folding Of Patternable Resist (PMMA) For 3D Lithography

A new method to fold free standing poly(methylmethacrylate) (PMMA) resist using e-beam exposure is developed and demonstrated. The results prove controllable folding of the patterned PMMA. An explanation of the folding mechanism is proposed based on experimental characterization and theoretical analysis. 3D lithography is achieved by attaching the patterned resist on an adjacent side wall by folding. Patterns are effectively transferred by depositing metal followed by a lift-off process.

The overall goal is to develop the science and technology necessary to realize the Nanostructured OrigamiTM 3D Fabrication and Assembly Process, a method of manufacturing multi-layered (3D) nano-systems from foldable nanopatterned surfaces (2D). This method has already been successfully demonstrated with ISN funding [W. Arora, et al, Appl. Phys. Lett. 88:053108, 2006] The final 3D configuration is obtained by first nanopatterning a functional 2D membrane and subsequently folding selected sections of the membrane sequentially in a pre-determined order. Since the nanopatterning step is on a surface, standard lithographic techniques from the semiconductor industry can be employed, as well as more recently invented nanopatterning methods including nano-imprint lithography. Nanostructured Origami™ allows complex geometries to be formed in addition to multi-layered devices, and it allows such devices to be formed in a single step, bypassing the processing difficulties associated with 3D nanostructures. The Nanostructured OrigamiTM process is also well suited to the hybrid integration of modalities (chemical, biological, electrical, optical, mechanical, etc.) which is a key enabling technology in numerous chemical and biological sensing and threat detection systems that are lightweight, low-cost and low-energy-consumption and thus portable to the battlefield.