Crash test dummies were first introduced in 1949, and they’ve come a long way since then. Manufacturer of crash test dummies Humanetics realized that car accidents affect people differently based on their age, size, and weight, and has created dummies that represent adult and child, male and female. Humanetics has also been developing a crash test dummy based on a particularly fragile and rapidly growing population – the elderly.
Medical innovations mean that more people are maintaining their health into later years, and are healthy enough to drive later in life. Health issues such as weight gain and fragile bones, which can make a person more prone to injury in an accident, are still concerns, though. In 2015, there were 40 million licensed drivers aged 65 or older in the United States – that’s one in every five. Humanetics has been focusing closely on this aging population and created a dummy that represents a 70-year-old woman.
The dummy is about 5’3″ and 160 pounds and is fleshy around the abdominal area, which can affect the body’s interaction with the seat belt. The entire torso also happens to be 3D printed.
“This is the first look at the future,” said Mike Beebe, CTO, Humanetics. “We’d been exploring the latest technologies and materials. But none of us knew at the time whether the materials could hold up in a crash.”
Engineers wanted to see if the more expensive steel components, such as the ribs, could be replaced with cheaper 3D printed parts made from plastic and rubber.
“If we could tackle the ribs, that would open up the door for some other organs,” said Beebe.
So how has it been working out so far? There have been a few snags, as the engineers were having difficulty finding a material that would withstand crash tests. The first plastic/rubber compound they used didn’t hold up for long.
“We 3D printed some ribs out of the plastic,” said design engineer Kris Sullenberger. “But after 20 hits, the ribs started to crack.”
Humanetics sought the advice of Adaptive Corporation, a digital-to-physical product lifecycle company. Adaptive Corporation’s suggestion? Onyx, a super-strong, carbon composite material reinforced with Kevlar fibers, produced by Markforged. According to Sullenberger, the ribs 3D printed from Onyx have held up through more than 150 impacts so far. The ribs are actually three times more durable than traditional steel ones and can be produced more quickly, though the cost is about the same. Encouraged, Humanetics went ahead to start 3D printing other parts from Onyx, including the shoulders, sternum, arms, spine, lumbar and scapula.
3D printing does allow for some cost savings within the company – by 3D printing molds for complex components rather than producing them from machined steel, Humanetics has been able to save 40 to 60 percent in labor and assembly costs.
Now Humanetics is looking at making its dummies more complex. Until now, the company has created its dummies with overall regions of the body, such as the thoracic or abdominal area, represented, but now it’s considering 3D printing individual organs in order to help understand how each one is affected by an impact – in yet another example, along with 3D printed organ models and surgical simulators, of how 3D printing can be used to save lives.
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[Source: Forbes / Images: Humanetics]
