Hedgehogs Hold the Secret to Preventing Concussions
Adam Rifkin stashed this in Concussions
Engineers use hedgehog-inspired biomimicry to craft better helmets. Findings show that in certain conditions, hedgehog spines can absorb as much, if not more, than industry standard impact-absorbing foam.
If you ever find yourself watching hedgehog go about its day, you’ll notice that they tend to fall out of trees — a lot. Wild hedgehogs climb trees as high as 30 feet, looking for insects and food to eat. Sometimes they fall by accident, other times they fall on purpose to evade a predator or because falling is a lot faster than climbing down.
As a hedgehog falls toward the ground, it keeps itself safe by rolling into a ball to surround itself with “spines” that absorb the impact. (Hedgehog spines are colloquially referred to as “quills,” which is the official term for what porcupines have. Hedgehog spines function differently, however, than porcupine quills.) It’s an effective method of protection — and one that humans want to steal.
“The animal walks away uninjured,” says Nathan Swift, chief operating officer at Hedgemon, a company that designs hedgehog-inspired helmets.
Hedgemon operates within the fairly new field of biomimicry, which looks to nature for solutions to human problems. Biomimicry combines science, engineering, design, and even business, says Bill Hsiung, chief science officer at Hedgemon and a biomimicry fellow at the University of Akron in Ohio. “Nature is kind of like a research lab by itself,” he says. “It’s already been doing trial and error for all kinds of different solutions for 3.8 billion years. Whatever’s left that’s still out there for us to study has been proven successful.”
The project to use hedgehog-inspired biomimicry to craft better helmets began about four years ago with a group of students in a class co-taught by professors from the University of Akron and the Cleveland Institute of Art. The idea was to find a biological model to address impact protection, says Swift.
Hedgemon is testing four by four squares of the liner, which will eventually be integrated into helmets.
Hedgemon’s study, entitled “Dynamic impact testing of hedgehog spines using a dual-arm crash pendulum,” was the first to look at “the impact energy absorption capability of hedgehog spines beyond anecdotal biological evidence.” They found that greater impact speed decreases durability but not initial energy absorption. “When samples are arranged in an orientation analogous to the natural model, hedgehog spines demonstrate impact absorption capabilities that confirm their role in the protection of hedgehogs during falls,” the researchers wrote. “This study demonstrates that in certain conditions, hedgehog spines can absorb as much, if not more, than industry standard impact-absorbing foam.”
Hedgehog-inspired helmets made to absorb rotational hits and protect against concussions would be particularly useful for football players. “The NFL has a gigantic problem right now. The concussion rate is through the roof, and we’re continuously seeing the detrimental long-term effects on retired players,” says Swift. “There are numerous lawsuits involving both the NFL and the helmet manufacturers, and the sport is losing both players and viewers, not to mention all the bad press the NFL gets. If this works, they’ll be interested, they want nothing more than for this problem to go away as quickly as possible.”
Top Reddit comment:
The Army has been working in this area for decades to improve helmets and has collaborated with the NFL and other organizations. There are designs that use things besides foam to get much improved performance but at higher cost, lower durability or lower temperature ranges. Unfortunately like most engineering problems best depends on how you define what's important.