3D printed auxetics

Walters, Peter

Abstract

The term 3D printing refers to the fabrication of physical objects directly from 3D computer aided design data. Also known as additive layer manufacturing and rapid prototyping, 3D printing generally works by solidifying, fusing or depositing materials layer-by-layer each layer being a cross-sectional horizontal slice of the object being built (1-3).
Because 3D printing requires no tooling, and because the 3D printed objects are built up layer-by-layer, it is possible to fabricate highly complex shapes and structures that would be difficult or impossible to make by conventional manufacturing techniques such as casting or machining. This is evidenced by the wide range of complex and sometimes fanciful objects which may be found in a Google image search for 3D printed objects. Such objects include complex lattices, objects nested within other objects, and even ready-made mechanisms with moving parts that require no assembly.
One area where the ability to fabricate complex objects is genuinely beneficial is in the field of Auxetics (4). Auxetic structures, having superior load carrying and form-following properties, have been proposed for aerospace, biomedical and sports equipment design.
Many auxetic structural designs take the form of complex 2.5D or 3D lattices. In this presentation we will demonstrate auxetic lattice structures which have been fabricated using a range of 3D printing techniques. The fabrication techniques will be illustrated and explained, and a potential application for 3D printed auxetics in the field of medical technology* will be introduced.
*This research has been undertaken in collaboration with Bristol Composites Institute (Prof Fabrizio Scarpa, Dr Ian Farrow and students) and the charity MS Research (Dr Rosie Jones, Angela Davies-Smith).
References
1/ Hull C (1986) Apparatus for production of three-dimensional objects by stereolithography. Patent 4575330, USA.
2/ Crump S (1992) Apparatus and method for creating three-dimensional objects. Patent 5121329, USA.
3/ Deckard CR, Beaman JJ, Darrah JF. (1992) Method for selective laser sintering with layerwise cross-scanning. Patent 5155324, USA.
4/ Evans KE and Alderson A (2000) Auxetic Materials. Advanced Materials12 No. 9

Citation

Walters, P. (2018, October). 3D printed auxetics. Presented at 4th VIPER School: Composite structures and auxetic systems, Bristol, UK

• Presentation Conference Type: Lecture
• Conference Name: 4th VIPER School: Composite structures and auxetic systems
• Conference Location: Bristol, UK
• Start Date: Oct 15, 2018
• End Date: Oct 18, 2018
• Acceptance Date: Oct 1, 2018
• Deposit Date: Oct 24, 2018
• Publicly Available Date: Oct 24, 2018
• Peer Reviewed: Not Peer Reviewed
• Keywords: auxetics, smart materials, 3D printing, design, medical
• Public URL: https://uwe-repository.worktribe.com/output/859607
• Related Public URLs: http://www.bristol.ac.uk/engineering/school-came/4th-viper-school/
• Additional Information: Title of Conference or Conference Proceedings : 4th VIPER School: Composite structures and auxetic systems