Injured sea turtle with 3D printed brace is growing, thriving

An injured sea turtle found in the cooling canal of a New Jersey power plant in 2013 is now growing and thriving at a California aquarium thanks to 3D printing.

Staff at the Birch Aquarium at Scripps Institution of Oceanography at the University of California, San Diego collaborated with the digital media laboratory at the university's Geisel Library to design, build and attach a 3D printed brace that fills a gap in the bottom right part of the loggerhead sea turtle's shell.

The brace, combined with a neoprene weight pocket, is expected to let her grow and thrive in the protected environment of the aquarium.

When the young turtle was rescued, she had a gap in her shell that was only part of her problems. She also had an abnormal curvature of her spine and paralyzed rear flippers.

Initial recovery efforts occurred at the nonprofit Marine Mammal Stranding Center in Brigantine, N.J., and then at the sea turtle care center at the nonprofit South Carolina Aquarium in Charleston, S.C.

The South Carolina facility sought a permanent home for the turtle and reached out to institutions accredited by the Association of Zoos and Aquariums.

Birch Aquarium offered its services, secured necessary approvals from the U.S. Department of the Interior's Fish and Wildlife Service and conducted a campaign that raised more than $50,000 to support the first year's housing and rehabilitative care for the turtle.

The turtle weighed 74.5 pounds on arrival at Birch Aquarium in November 2014. Since then, she has gained more than 130 pounds, but the team wanted to address her major health issues, including the damaged shell.

The lab's 3D scans identified possible design solutions, and UC San Diego's Thornton Hospital's computer tomography scans were used to monitor changes in the shell as she grew.

To replace the broken shell, the digital media lab used an i3 MK2 fused deposition modeling printer from Prusa Research sro of Prague, Czech Republic, and made the final 3D print on a 2+ FDM printer from Ultimaker BV of Geldermalsen, the Netherlands.

Nozzles of 0.8 millimeters on the Ultimaker maximized clarity of the glycol-modified PET filaments, said Scott Mcavoy, technical and media specialist at the library.

The lab procured white translucent t-glase-brand PETG filaments from taulman3D LLC of St. Peters, Mo., and used about a half-pound of the materials to print 9-by-5-by-2-inch brace.

Mcavoy noted the processing was difficult "due to material and clarity adjustments."

Technicians used a two-part underwater marine epoxy compound to attach the brace, which prevents the turtle's shell from curving further downward and promotes normal growth.

Separately, the team attached a Velcro neoprene weight pocket to provide neutral buoyancy while the turtle rests in the aquarium's Hall of Fishes' Magdalena Bay habitat.

As the turtle grows potentially to 250 pounds, she will outgrow the brace and be fitted for a larger one.