The University of Michigan researchers are focused on creating a helmet that absorbs the negative effects of impulse –- the secondary effect of an initial force or hit that may be the cause of brain injury in football players. They explain that impulse is what gives objects momentum and energy. Given the speed and weight of current football players, helmets need to be designed to block or reduce the forces of both impulse and impact.
In developing their prototype, the researchers found studies from 70 years ago that blamed impulse for damage caused by the quick, hard hits sustained in football. Yet, the results of those studies don’t seem to have made it into the long-standing designs used today.
After testing various materials in table-top collision simulators, the researchers found that the Mitigatium prototype did the best job, with a 20 percent reduction in impulse and a 30 percent reduction in peak pressure.
The three layers within the Mitigatium (seen above) include an initial layer of hard polycarbonate similar to what is used in helmet shells today, a second layer consisting of a flexible plastic, and a third layer that is described as having the consistency of dried tar. The first two layers work in tandem to reflect most of the initial force or incoming shock wave, while the third layer dissipates that force to reduce it even further. The overall effect is reduced impact to the brain.
There’s no indication as to when a helmet using Mitigatium might be put into production, since more studies and research must be completed. Other universities and companies are engaged in similar projects, including the University of Washington with its Zero1 helmet and Riddell’s Speedflex that was introduced in 2014.
Featuring an outer shell that yields upon impact like a car bumper, the Zero1 helmet is expected to be available to select NFL and NCAA football teams this spring and be worn in the 2016-17 season.
The Riddell Speedflex is designed with “crumple zones,” which will protect a player’s head upon impact. It is now generally accepted that it’s safer for vehicles to feature impact-absorbing crumple zones. With that in mind, that’s what Riddell’s new SpeedFlex helmet does … Just to be clear, the SpeedFlex doesn’t actually crumple under pressure. It does, however, have a built-in hinged rubber-padded panel located on the front near the top. In head-on collisions with other players (or the ground), this panel gives by up to a quarter of an inch (6 mm), helping to absorb the impact.