Researchers advance concept of “4-D” printing technology using shape memory polymer fibers
22 October 2013
Researchers at the University of Colorado Boulder and Singapore University of Technology and Design have added a “fourth dimension” to additive manufacturing technology, opening up possibilities for the creation and use of adaptive, composite materials in manufacturing, packaging and biomedical applications. The research could help provide a new approach to creating reversible or tunable 3D surfaces and solids in engineering such as the composite shells of complex shapes used in automobiles, aircraft and antennas.
A team led by H. Jerry Qi, associate professor of mechanical engineering at CU-Boulder, and his collaborator Martin L. Dunn of the Singapore University of Technology and Design incorporated shape memory polymer fibers into the composite materials used in conventional 3D printing (additive manufacturing), which results in the production of an object fixed in one shape that can later be changed to take on a new shape.
In this work, the initial configuration is created by 3D printing, and then the programmed action of the shape memory fibers creates time dependence of the configuration—the 4D aspect.
—Martin Dunn
The 4D printing concept, which allows materials to self-assemble into 3D structures, was initially proposed by Massachusetts Institute of Technology faculty member Skylar Tibbits in April of this year. Tibbits and his team combined a strand of plastic with a layer made out of smart material that could self-assemble in water.
We advanced this concept by creating composite materials that can morph into several different, complicated shapes based on a different physical mechanism. The secret of using shape memory polymer fibers to generate desired shape changes of the composite material is how the architecture of the fibers is designed, including their location, orientation and other factors.
—Martin Dunn
The team’s findings were published last month in the journal Applied Physics Letters. The paper was co-authored by Qi “Kevin” Ge, who joined MIT as a postdoctoral research associate in September.
The fascinating thing is that these shapes are defined during the design stage, which was not achievable a few years ago.
—H. Jerry Qi
The CU-Boulder team demonstrated that the orientation and location of the fibers within the composite determines the degree of shape memory effects like folding, curling, stretching or twisting. The researchers also showed the ability to control those effects by heating or cooling the composite material.
Qi says 3D printing technology, which has existed for about three decades, has only recently advanced to the point that active fibers can be incorporated into the composites so their behavior can be predictably controlled when the object is subjected to thermal and mechanical forces.
Resources
Ge, Qi and Qi, H. Jerry and Dunn, Martin L. (2013) “Active materials by four-dimension printing”, Applied Physics Letters, 103, 131901 doi: 10.1063/1.4819837
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