|Posted on February 28, 2016 at 8:20 PM|
Kirigami is an Japanese art form in which paper is folded and cut to reveal beautiful intricate patterns. Prof. Shu Yang of University of Pennsylvania was inspired by this ancient art in order to transform materials that don’t stretch (her “paper” into flexible and stretchable sheets that can be moulded into 3-D shapes using a technique she calls “fractal cut patterning” (her nano-kirigami). Look at her kirigami blog, including paper cutting that you can do at home.
(Prof. Yang playing with her son).
In her 2016 MRS Bulletin perspective on nano-kirigami, Shu Yang explains how she introduces cuts that divide the material into square or triangular rotational units. These rigid units act as hinges to help fold the material, keeping the material strain-free. Yang has used two cut patterns – ‘hierarchal’ and ‘motif alternation’. The ‘hierarchal’ pattern subdivides the original square into smaller ones by repeating the cut pattern. The ‘motif alternation’ applies a cut homogeneously throughout the material. This has allowed Yang’s group to deposit an electron-conducting thin film of (otherwise rigid) carbon nanotubes on a silicone rubber sheet stretched over a spherical baseball. This system can then be used to power a flexible Light-Emitting Diode (LED).
Shu Yang has a number of really cool studies in her group: She has developed a polymer material that changes color depending on how hard it is hit, which could be used on a helmet to indicate how hard a hit they took and hence warn of possible risk of concussion. She is working on smart and self-cleaning windows, and on mimicking a giant clam’s ability to act as a solar greenhouse.
(Prof. Yang helping her daughter with studies).
Prof. Yang is a Professor in Material Science and Engineering and Chemical and Biomolecular Engineering at University of Pennsylvania. She has many awards: the 2015-16 George H. Heilmeier Faculty Award for Excellence in Research, an NSF CAREER Award, a Unilever Award in Polymer Science and Engineering 2001 and an ICI award in Applied Polymer Science.
- Written by Nakita Sengar, edited by Paulette Clancy
(Photo credit: Provided by and used with permission from Prof. Shu Yang).