The first 3D printed ribs, using a plastic/rubber compound, matched many of the properties Humanetics were looking for, but they didn’t survive the rigors of crash testing. “We 3D printed some ribs out of the plastic,” said design engineer Kris Sullenberger. “But after 20 hits, the ribs started to crack.”
Humanetics then turned to Adaptive Corporation, a digital-to-physical product lifecycle company, which suggested using Onyx, a carbon-composite material reinforced with continuous Kevlar fibers, developed by MarkForged, a Massachusetts-based maker of 3D printers.
“We’ve inflicted over 150 impacts to those Markforged-produced ribs to date,” Sullenberger said. “And we haven’t broken a rib yet.”
That led Humanetics to print other body parts, including the shoulder, spine, lumbar, scapula, sternum and arms.
The 3D-printed parts cost about the same as the steel ones but they are three times more durable and can be made more quickly.
Manufacturing a set of ribs conventionally used to take two to three weeks. Now they can print a single rib in 24 hours and a full set in a week.
Humanetics has also found it can save 40 – 60 percent in assembly and labor costs by 3D-printing molds for complex components rather than producing them from machined steel.
The company is also exploring the use of 3D printing to create specific organs for test dummies.
Humanetics typically creates test systems to represent overall regions of the body (such as the thoracic or abdominal area) rather than an individual heart or lung. By 3D printing organs like a liver or a spleen, researchers can better understand how each one is affected by an impact.
So far, Humanetics has made just two of the elderly dummies, which are undergoing further testing. But amid a growing, aging population, the focus on elderly passengers seems to be justified.
Baby Boomers now in their 60s and 70s are often heavier than they were on average just a few decades ago, yet healthy enough to be driving into their 80s and beyond. In 2015, there were more than 40 million licensed drivers aged 65 and older in the United States, representing one in every five drivers on American roads.
This article was first published by Joann Muller, FORBES STAFF