Author(s) Baris Bircan, Marc Miskin, Robert J. Lang, Michael Cao, Kyle Dorsey, Muhammad Salim, Wei Wang, David Muller, Paul McEuen, and Itai Cohen
Origami design principles are scale invariant and enable direct miniaturization of origami
structures provided the sheets used for folding have equal thickness to length ratios. Recently, seminal steps have been taken to fabricate microscale origami using unidirectionally actuated sheets with nanoscale thickness. Here, we extend the full power of origami-inspired fabrication to nanoscale sheets by engineering bidirectional folding with 4 nanometer thick atomic layer deposition (ALD) SiN x - SiO 2 bilayer films. Strain differentials within these bilayers result in bending, producing microscopic radii of curvature. We lithographically pattern these bilayers and localize the bending using rigid panels to fabricate a variety of complex micro-origami devices. Upon release, these devices self-fold according to prescribed patterns. Our approach combines planar semiconductor microfabrication methods with computerized origami design, making it easy to fabricate and deploy such microstructures en masse. These devices represent an important step forward in the fabrication and assembly of deployable micromechanical systems that can interact with and manipulate micro and nanoscale environments.
Nano Letters, June 11, 2020
This work describes a technology for generating self-folding micro-origami using ultra-thin ALD films.