title: Guided fracture of films on soft substrates to create micro/nano-feature arrays with controlled periodicity.
abstract: While the formation of cracks is often stochastic and considered undesirable, controlled fracture would enable rapid and low cost manufacture of micro/nanostructures. Here, we report a propagation-controlled technique to guide fracture of thin films supported on soft substrates to create crack arrays with highly controlled periodicity. Precision crack patterns are obtained by the use of strategically positioned stress-focusing V-notch features under conditions of slow application of strain to a degree where the notch features and intrinsic crack spacing match. This simple but robust approach provides a variety of precisely spaced crack arrays on both flat and curved surfaces. The general principles are applicable to a wide variety of multi-layered materials systems because the method does not require the careful control of defects associated with initiation-controlled approaches. There are also no intrinsic limitations on the area over which such patterning can be performed opening the way for large area micro/nano-manufacturing.
authors.affiliation: 1] Department of Biomedical Engineering, College of Engineering, University of Michigan, 2200 Bonisteel Blvd, Ann Arbor, MI 48109, USA [2] Macromolecular Science and Engineering Center, College of Engineering, University of Michigan, 2300 Hayward St., Ann Arbor, MI 48109, USA.
authors.forename: Byoung Choul
authors.initials: BC
authors.lastname: Kim
authors.forename: Toshiki
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Christopher
authors.initials: C
authors.lastname: Moraes
authors.forename: Jiexi
authors.initials: J
authors.lastname: Huang
authors.forename: M D
authors.initials: MD
authors.lastname: Thouless
authors.forename: Shuichi
authors.initials: S
authors.lastname: Takayama