How It Works
Bones preserve. Muscles, ligaments, and cartilage don?t. So while modern paleontologists can piece together skeletons of long-gone dinosaurs, they can?t see the exact size and shape of the tissue that allowed these terrible lizards to be moving creatures.
So Lacovara?s study started from an assumption. His team is focused on the class of dinosaurs called sauropods (think of a Brachiosaurus) that had huge tails and necks and were among the largest animals ever to roam the earth. "You can?t grow to be 60 tons if you aren?t really careful with every calorie you take in," Lacovara says. So, he thinks, to reach the colossal sizes that they did, sauropods must have had an anatomy that worked at the height of efficiency. "The most efficient way to use these bones is probably something pretty close to the truth."
The first dinosaur fossil the team is working on is the forearm of a giant yet-to-be-named sauropod that Lacovera discovered in Egypt in 2000. To begin, he uses a detailed laser scanner in his labs to create an exact 3D digital record of the fossil he wants to study. He can also correct this digital record for damages that occurred to the bone during the millions of years of fossilization.
When the detailed scan is complete, Lacovara turns it over to biomechanical engineer Sorin Siegler. Siegler studies human bone mechanics, and his part of the process is to create virtual models that let him study different ways that those dinosaur bones could move in tandem, and thereby find the most efficient system. Siegler?s work creates a walking model dinosaur on the computer. But to really understand dino locomotion, the researchers need to study it in the real world. That?s where mechanical engineer and roboticist James Tangorra comes in.
"It?s very difficult to model the real world well. The robotic system has the real world at its disposal, so we get much more complex and real world responses," Tangorra says. He can reproduce scaled-down replicas of Lacovara?s fossil scans in a matter of hours with a 3D printer. The printer builds these models by squeezing out tiny beads of thermoplastic?a type of plastic that quickly hardens when it is cooled?layer-by-layer until the reproduction is complete.
Once the faux bone is built, Tangorra uses a combination of materials to replicate the dinosaur?s soft tissues that have been lost from the fossil record. To replicate stiff tendons, he uses low-stretch fishing lines. Tangorra casts pourable urethanes into the shapes of the cartilage; his team weaves elastic fabric to replicate the flexibility of tendons.
Finally, Tangorra attaches a motor similar to those used in RC planes. Then the team can put Siegler?s anotomical designs to the test with a walking robot dinosaur.
A Peek Into the Past
Ultimately the work by the three Drexel scientists and their teams is a collaborative effort between paleontology, computer-based physics modeling, and robotics, to fill in holes of knowledge about the long-extinct dinosaurs.
"A lot of this with the dinosaurs is speculative," Tangorra says. "What?s hopefully changing is that we will speculate something occurred in a dinosaur, and then we are going to be able to look at it in a simulation and then a robotic simulation and see if that speculation is true."
Lacovara thinks that his team will have a working dinosaur limb by the end of 2012 and a complete dinosaur within two years. And soon thereafter, their robot dino could be revealing how motion looked millions of years ago.
"I think we are closer along the road to really understanding these creatures and how they moved," Lacovara says.
san onofre paula deen birth control recall the jerk nick carter leslie carter aaron carter sister
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.