Programming the shape-shifting of flat soft matter: from self-rolling/self-twisting materials to self-folding origami. Issue 6 (2nd September 2016)

• Record Type: Journal Article
• Authors: Janbaz, S.; Hedayati, R.; Zadpoor, A. A.
• Is Part Of: Materials horizons. Volume 3:Issue 6(2016:Nov.)
• Page Start: 536
• Page End: 547
• Publication Date: 2016-09-02
• Subjects: Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6mh00195e
• Languages: English
• ISSNs: 2051-6347

Abstract

Abstract : Rational programming of the shape-shifting behavior of flat materials (possibly decorated with complex surface features) to create complex three-dimensional structures. Abstract : Nature uses various activation mechanisms to program complex transformations in the shape and functionality of living organisms. Inspired by such natural events, we aimed to develop initially flat ( i.e. two-dimensional) programmable materials that, when triggered by a stimulus such as temperature, could self-transform their shape into a complex three-dimensional geometry. A two-dimensional starting point enables full access to the surface, e.g. for (nano-)patterning purposes, which is not available in most other manufacturing techniques including additive manufacturing techniques and molding. We used different arrangements of bi- and multi-layers of a shape memory polymer (SMP) and hyperelastic polymers to program four basic modes of shape-shifting including self-rolling, self-twisting (self-helixing), combined self-rolling and self-wrinkling, and wave-like strips. The effects of various programming variables such as the thermomechanical properties of the hyperelastic layer, dimensions of the bi- and multi-layer strips, and activation temperature on the morphology of the resulting three-dimensional objects were studied experimentally and were found to cause as much as 10-fold change in the relevant dimensions. Some of the above-mentioned modes of shape-shifting were then integrated into other two-dimensional constructs to obtain self-twisting DNA-inspired structures, programmed pattern development in cellular solids, self-folding origami, and self-organizing fibers. Furthermore, the possibility of incorporating multiple surface patterns into one single piece of shape-transforming material is demonstrated using ultraviolet-cured photopolymers.