A synthetic material identical to elephant ivory that can be 3D printed at high resolution – called “Digory” for “digital ivory” – was used to restore historical works of art that included ivory made from tusks.
Researchers say it will be invaluable for restoration projects – real elephant ivory has often been used in important works of art for thousands of years, especially in ancient China – and that greater awareness of its use could help prevent the poaching that the Wild elephant survival threatens many parts of the world. “There should be no demand for ivory made from animals at all. There are so many alternatives, ”says Thaddäa Rath from the Vienna University of Technology. “No piece of jewelry or decoration is worth the death of a single animal.”
Rath and a team led by materials scientist Jürgen Stampfl developed Digory, which consists of a translucent mixture of synthetic acrylic resin and tricalcium phosphate particles. They used it to recreate several tiny ivory ornaments that had been lost from an ornate 17th century coffin in a church in Mauerbach, Austria.
Elephant ivory used to be widely used in such works of art, but international ivory trade has been banned since 1989. Restorers no longer use real elephant ivory, and it has become extremely expensive, even if international law allows its use in small quantities.
Instead, the research team and Cubicure, a university-spun precision 3D printing company, used Digory to create 18 of the finely carved and decorative ivory capitals missing from the Mauerbach box.
There are other synthetic ivory as well, but the researchers say Digory is the first that can be 3D printed in high resolution using a technique called stereolithography. Laser light is used to cross-link polymers within the 3D ink and build up complex shapes layer by layer.
Digory has the same optical and mechanical properties as elephant ivory, say the researchers. It can be color coordinated and made into any shape. It can then be polished, carved, drilled or glued like real ivory. The dark veins that are often visible in elephant ivory can also be reproduced by touching up with a paint mixture that includes black tea.
Ulrike Wegst, a materials scientist and engineer at Northeastern University in Boston, who studies bio-inspired materials, says Digory is a “timely addition” to the field that could help prevent further elephant ivory poaching. “The additive process of 3D printing is ideally suited for the material and inexpensive reproduction of complicated old designs as well as for the production of elaborate new designs that would otherwise require highly skilled artisans,” she says.
Wegst, who was not involved in the research, notes that it will be interesting to see whether Digory “ages” similar to real ivory, which changes color over time, and whether the additives used in its manufacture can prevent it that it becomes brittle like some other polymers.