Low-density, expandable, but strong materials that can be 3D printed and then reconfigured using techniques akin to the paper-folding art of origami, might be used in future biomedical devices and equipment for space exploration. The approach avoids the need for the usually complicated multi-step procedures needed to build smaller component parts into a sophisticated structure. [Z. Zhao et al. Soft Matter (2018); 14 (39): 8051; DOI: 10.1039/c8sm01341a]
"What we have here is the proof of concept of an integrated system for manufacturing complex origami," explains Glaucio Paulino of the Georgia Institute of Technology. "It has tremendous potential applications."
The researchers used a relatively new kind of 3D printing called Digital Light Processing (DLP) to make their origami structures. DLP prints successive layers of a liquid polymer resin that is then cured, or hardened using ultraviolet light. The products can hold significant weight and also be folded and refolded repeatedly. The structures are the next step on from Paulino's 2015 "zippered tubes," which were made from paper and required gluing together.
In this latest iteration of the research, the team developed a new resin based on 50 percent by weight of commercial aliphatic urethane diacrylate, 25% by weight of glycidyl methacrylate monomer and 25% isodecyl acrylate monomer with various curing additives. The team was looking to produce a material that is not only soft but can also be folded hundreds of times without breaking. This resin can be formed into tiny, but highly resilient hinges. These hinges, lie along the folds and are made of a thinner layer of resin than the larger panels of which they are part with the thicker panels making up the bulk of the structure.
The team used DLP to create several origami structures from this resin ranging from the individual origami cells from which the zippered tubes are composed to a complex bridge composed of many zippered tubes. Their tests showed that these structures can carry about 100 times their weight. The next step will be to make the printing process easier and also find ways to print other materials with different properties. Paulino's team has already designed a novel and convoluted origami structure in silico that the researchers hope to replicate in the real world that could bring this field to life.
David Bradley blogs at Sciencebase Science Blog and tweets @sciencebase.