Shape memory polymer hexachiral auxetic structures with tunable stiffness

Rossiter, Jonathan; Takashima, Kazuto; Scarpa, Fabrizio; Walters, Peter; Mukai, Toshiharu

Abstract

Planar auxetic structures have the potential to impact on a wide range of applications from deployable and morphing structures to space-filling composite and medical treatments. The ability to fabricate auxetics from smart materials greatly enhances this facility by building in controllable actuation and deployment. A smart auxetic device can be compressed and fixed into a storage state. When deployment is required the device can be appropriately stimulated and the stored elastic energy is released, resulting in a marked structural expansion. Instead of using a conventional external actuator to drive deployment the material is made to undergo phase transition where one stimulus (e.g. heat) initiates a mechanical response. Here we show how smart material auxetics can be realized using a thermally responsive shape memory polymer composites. We show how a shape memory polymer auxetic hexachiral structure can be tailored to provide a tunable stiffness response in its fully deployed state by varying the angle of inter-hub connections, and yet is still able to undergo thermally stimulated deployment. © 2014 IOP Publishing Ltd.

• Journal Article Type: Article
• Publication Date: Jan 1, 2014
• Journal: Smart Materials and Structures
• Print ISSN: 0964-1726
• Electronic ISSN: 1361-665X
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 23
• Issue: 4
• DOI: https://doi.org/10.1088/0964-1726/23/4/045007
• Keywords: soft matter, liquids and polymers, condensed matter
• Public URL: https://uwe-repository.worktribe.com/output/819827
• Publisher URL: http://dx.doi.org/10.1088/0964-1726/23/4/045007