While it’s not your average prototyping project, today’s photopolymer materials proved to be well suited for replicating the skeletal remains of a 77-million year old dinosaur. Leonardo is the mummified dinosaur in question. With the help of Ford Motor Co. and Huntsman Advanced Materials among other companies, its remains are being prepared to go “on tour” for display at museums throughout the U.S.
The first step in the process was to build a high quality stereolithography (SL) model of the rare
22-foot-long fossil. Built in 30 different photopolymer blocks, the model replicates intricate details preserved in the unique mummy including skin, scales, muscle and footpads. Among the materials used for the model are Huntsman’s RenShape® SL 7510 multifunctional resin and RenShape® SL 7800 and SL 7810 hybrid photopolymers.
Ford engineers built each 20 in. x 20 in. x 20 in. model section from data produced by a white light scan of the dinosaur. The 300 dpi scan is accurate to 0.25 mm. Combined with the SL resin, the team was able to replicate intricate detail, including fossil features as small as a grain of sand. The robust model parts also showed excellent surface quality straight from the vat, reducing secondary finishing steps. The amber-colored RenShape® SL 7800 photopolymer and white RenShape® SL 7810 ABS-like resin reduced processing time while maintaining good green strength.
The model of Leonardo is made up of 30 different blocks of SL material including Huntsman’s RenShape® SL 7510 multifunctional resin and RenShape® SL 7800 and SL 7810 hybrid photopolymers. (Photo by of Al Hembd.)
Once all model pieces were complete, they were assembled and bonded together. A silicone rubber mold is now being built along with a polyurethane casting. The painted polyurethane dinosaur will be virtually indistinguishable from the mummified Leonardo fossil and will be tough enough to withstand the rigors of shipping and handling during the multi-location tour.
Discovered in Montana, Leonardo is a mummified duck-billed dinosaur that died when he was three or four years old. One of the most complete brachylophosaurus dinosaur fossils found to date, he was a plant-eater that could walk on four legs as well as two. He had a sharp beak at the front of his large head so that he could easily tear tough leaves from plants and trees.
Leonardo is the subject of particular scientific interest because his mummified remains offer unprecedented detail. For example, the fossil contains varied skin textures over different parts of his body providing scientists with clues as to how Leonardo lived. Experts also discovered that the dinosaur had the same digestive organ known as a crop that is characteristic of modern plant-eating birds. He was even preserved with the remains of his last meal — a salad of ferns, magnolias and conifers — still in his stomach along with pollen from more than 40 different plants that are being studied by scholars. Furthermore, paleontologists are examining his fossilized muscles and the pads at the bottom of his three-toed foot to learn about his range of motion.
Leonardo is one of the most complete brachylophosaurus dinosaur fossils found to date. His mummified remains offer unprecedented detail including varied skin textures over different parts of his body, muscles and digestive organs. (Photo by Grant Delin.)
Dr. Robert T. Bakker, Leonardo Science Team member, describes this amazing fossil as “more complete, better than any other dinosaur fossil found. Leonardo speaks to us. This fossil is so complete, it answers questions we never thought to ask.”
Huntsman Advanced Materials