Photonics Brings Dinosaur to Life

R. Winn Hardin

SAN ANSELMO, Calif. -- Museums, faced with the dilemma of making their displays more interactive and paying top dollar for fossils, have turned to laser scanning as a solution to their troubles.
"It's a shame, but museums are losing attendance," said Scansite's Lisa Federici. "So they've finally taken the turn that they'd like to bring their exhibits more into the 20th century."
Doing that means bringing priceless pieces of art and archaeology to life. Scansite, a service bureau that focuses on 3-D digital cloning, used laser scanning
devices from Cyberware of Monterey, Calif., to digitize a Tyrannosaurus Rex named Sue for that very purpose. The dinosaur, which sold to the Chicago Field Museum for $8.4 million, had each bone scanned through one of two methods, cylindrical or linear.

Scanning the surface
According to Cyberware's Steve Adelman, the systems use helium-neon lasers from Melles Griot to scan an object. A cylindrical lens spreads the beam into a 300-mm-long plane of light. The light bounces off the object, which sits on a rotating pedestal. The light then passes through a filter to dispose of ambient light, and a 640 3 480-pixel charge-coupled device chip from Texas Instruments captures the coherent outline of the image.
Federici said a single object can take more than two hours to process, depending on its shape and the number of scans needed to capture every nook and cranny. The resulting digital file captures the object down to 0.1-mm resolution, saving the original piece for all time.
Scientists benefit as well, Federici said, because the digital file offers more accurate volume and distance measurements than those taken with mechanical means. "Plus, you can't ship these [fossils] around the world, but they can ship the data. Ten people can study it without having the original piece."
Dino-data like this have produced new insights into how muscle is connected to bones, revealing a clearer picture of dinosaur anatomy.