A 3-D printed waffle material, a matrixed honeycomb with a stiff outside cover and a washable pad of different layered fabrics have all made the final cut in the search for the next-generation sports helmet.
Soft, squishy materials are out of bounds when it comes to designing equipment to protect the heads and other body parts of athletes and soldiers. What the team judging the Head Health Challenge is looking for is something much smarter.
The result ends up being the layered look. The five finalists in the competition all have what the experts at the National Institute of Standards and Technology (NIST) called "architecture."
They're looking for materials that can absorb the impact of two linebackers butting heads so their brains don't bounce around inside their skulls, or that can slip smoothly to the side as a soccer player hits the turf, preventing the torque that can tear delicate brain tissue.
"The ultimate protective material would deform, all that energy would be locked up in the material, and it would not rebound," said NIST materials scientist Michael Riley, who tested each entry on a device that uses accelerometers, load sensors and a high-speed camera to document how a material sample responds to having, say, a heavy weight dropped on it.
"These are made out of pretty much common existing materials," Riley says as he demonstrates the winning products. "But what they have looked at are different ways of architecting, layering, the combination of different materials so that they perform very well."
Each winner of the contest — sponsored by NIST, The National Football League, Under Armour and GE — gets $250,000 to tweak their entries and try to make them into a usable product.
Concussions are a hot issue in the U.S. Emergency room visits for head injuries have soared — the Centers for Disease Control and Prevention says nearly half a million U.S. children are treated in emergency departments every year for brain injuries that include concussion.
Just last month the U.S. Soccer Federation agreed to ban heading the ball for kids under 10 after a class action lawsuit alleged more than 46,000 high school soccer players suffered concussions in 2010.
The White House has made the concussion issue a priority, and kids' sports leagues are piling on to try and limit head injuries. The Head Health Challenge arose out of the Obama administration's initiative.
The NFL is battling its own crisis as revelations come one after another, showing chronic traumatic encephalopathy or CTE in players who suffered repeated head blows. The latest: an autopsy showed NFL Hall of Famer and "Monday Night Football" broadcaster Frank Gifford, who died in August of natural causes at the age of 84, had CTE.
A study by Boston University and the Department of Veteran Affairs found evidence of CTE in 96 percent of the 91 former NFL players tested. The NFL is facing a billion-dollar settlement to players suffering from damaging neurological conditions.
And in a report released this week in the journal Radiology, researchers said they found brain scarring in more than half of veterans who suffered blast-related mild traumatic brain injury. "This paper is just the tip of the iceberg," said Dr. Gerard Riedy of the Walter Reed National Military Medical Center in Bethesda, Maryland, who led the study.
"We have several more papers coming up that build on these findings and look at brain function, brain wiring, connectivity and perfusion, or brain blood flow."
So there's a lot of pressure to design a better helmet that can stop this brain damage from happening in the first place.
Better materials can do this by absorbing the energy from an impact, and moving sideways so the head doesn't have to, says Mike Fasolka, deputy director of NIST's Material Measurement Laboratory.
"You push your head sideways, it's actually the rotation that's believed to cause a lot of that traumatic head injury," he said.
The five winners achieve the goals in different ways.
Alba Technic, LLC of Winthrop, Maine submitted an orange and black layered honeycomb material whose hard shell outer layer spreads the energy of an impact. "This one works really well in terms of absorbing a lot of energy on impact with not a lot of rebound," said Riley.
Charles Owen Inc. of Lincolnton, Georgia submitted a white, corrugated sheet made using a 3-D printer. Its strength is its flexibility, said Fasolka. "The materials are flocked, they are furry. You can change the length of the fur. You can change its density. You can change the strut width," he said.
"You could also change the grid size, the pattern itself and adjust each of those so that the pattern in part of the helmet is optimized for the response you need there," Riley added.
Corsair Innovations of Plymouth, Massachusetts won with its layers of stretchy textiles that slide against one another, with a potential to limit the shear forces of an impact. Plus it's washable - a big advantage in something that sweaty people might wear.
Dynamic Research Inc. of Torrance, California and 6D Helmets LLC made a sandwich with two hard layers supported by what look like foam earplugs that absorb both impact and shear. "This stuff is good at absorbing energy," Fasolka said.
And a team at the University of Michigan came up with a lightweight composite that includes a viscoelastic material.
Now the winners can take their money and advice from the NIST team and other judges to try to improve their inventions. A final winner, after the tweaks, will get a $500,000 grand prize.
The end users won't just be sports helmet manufacturers or military suppliers.
"At this point, we think a lot of them have potential in other protection equipment - shoulder pads, kidney pads, chest protectors, basically any of the different pad materials that you might use in contact sports," Riley said.
"There's also potential for some of the materials to be used as underlayment under the turf. One of the big sources of injury are players hitting the ground too hard."