PT  - JOURNAL ARTICLE
AU  - Ding, Zhen
AU  - Yuan, Chao
AU  - Peng, Xirui
AU  - Wang, Tiejun
AU  - Qi, H. Jerry
AU  - Dunn, Martin L.
TI  - Direct 4D printing via active composite materials
AID  - 10.1126/sciadv.1602890
DP  - 2017 Apr 01
TA  - Science Advances
PG  - e1602890
VI  - 3
IP  - 4
4099  - http://advances.sciencemag.org/content/3/4/e1602890.short
4100  - http://advances.sciencemag.org/content/3/4/e1602890.full
SO  - Sci Adv2017 Apr 01; 3
AB  - We describe an approach to print composite polymers in high-resolution three-dimensional (3D) architectures that can be rapidly transformed to a new permanent configuration directly by heating. The permanent shape of a component results from the programmed time evolution of the printed shape upon heating via the design of the architecture and process parameters of a composite consisting of a glassy shape memory polymer and an elastomer that is programmed with a built-in compressive strain during photopolymerization. Upon heating, the shape memory polymer softens, releases the constraint on the strained elastomer, and allows the object to transform into a new permanent shape, which can then be reprogrammed into multiple subsequent shapes. Our key advance, the markedly simplified creation of high-resolution complex 3D reprogrammable structures, promises to enable myriad applications across domains, including medical technology, aerospace, and consumer products, and even suggests a new paradigm in product design, where components are simultaneously designed to inhabit multiple configurations during service.