title: Engineering the shape and structure of materials by fractal cut.
abstract: In this paper we discuss the transformation of a sheet of material into a wide range of desired shapes and patterns by introducing a set of simple cuts in a multilevel hierarchy with different motifs. Each choice of hierarchical cut motif and cut level allows the material to expand into a unique structure with a unique set of properties. We can reverse-engineer the desired expanded geometries to find the requisite cut pattern to produce it without changing the physical properties of the initial material. The concept was experimentally realized and applied to create an electrode that expands to >800% the original area with only very minor stretching of the underlying material. The generality of our approach greatly expands the design space for materials so that they can be tuned for diverse applications.
authors.affiliation: High Temperature Energy Materials Research Center and.
authors.forename: Yigil
authors.initials: Y
authors.lastname: Cho
authors.affiliation: High Temperature Energy Materials Research Center and.
authors.forename: Joong-Ho
authors.initials: JH
authors.lastname: Shin
authors.affiliation: High Temperature Energy Materials Research Center and.
authors.forename: Avelino
authors.initials: A
authors.lastname: Costa
authors.affiliation: Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea;
authors.forename: Tae Ann
authors.initials: TA
authors.lastname: Kim
authors.affiliation: Graduate Group in Applied Mathematics and Computational Science and.
authors.forename: Valentin
authors.initials: V
authors.lastname: Kunin
authors.affiliation: Departments of Nuclear Science and Engineering, and Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139; and.
authors.forename: Ju
authors.initials: J
authors.lastname: Li
authors.affiliation: Departments of Materials Science and Engineering and.
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Departments of Materials Science and Engineering and.
authors.forename: Shu
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Heung Nam
authors.initials: HN
authors.lastname: Han
authors.affiliation: High Temperature Energy Materials Research Center and insukchoi@kist.re.kr.
authors.forename: In-Suk
authors.initials: IS
authors.lastname: Choi
authors.affiliation: Departments of Materials Science and Engineering and Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104;
authors.forename: David J
authors.initials: DJ
authors.lastname: Srolovitz
keywords: deformability; differentiation; expandability; flexibility; patterning