Science and Bicycling Meet In a New Helmet Design
John Timmer from Ars Technica got a chance to take a look at Trek’s new bicycle helmet that they claim offers “the first major change in helmet technology in years,” and is backed up with peer-reviewed science. Here’s an excerpt from Timmer’s report: WaveCel is the product of orthopedic surgeon Steve Madey and a biomedical engineer named Michael Bottlang. The two had been working on a variety of ideas related to medical issues and protective gear, funded in part by federal grant money. When considering the idea of a lightweight material that could evenly distribute forces, Bottlang told Ars that they first focused on a honeycomb pattern. But they found that it was actually too robust — the honeycomb wouldn’t collapse until a lot of force had been applied, and then it would fail suddenly.
The design they eventually developed has a shape that allows flexing almost immediately when force is applied. “It starts to glide right away,” Bottlang said. The manufacturing technique creates a clear point of failure that allows more extensive flexing once a certain level of force is exceeded — part of the structure will fold over rather than experiencing a complete failure. Then, once folded, the polymer it’s made of will allow neighboring cells to glide over each other. This provides some resistance even after the structure has collapsed. For the helmet, a patch of this material is attached to the inside of a more traditional EPS helmet, which provides impact resistance. But the WaveCel mesh is allowed to float within the helmet and can absorb much of the force of off-axis impacts. The thin strips of soft material that cushion the helmet where it rests on the head (also found in more traditional helmets) are attached directly to the WaveCel mesh.
It looks more uncomfortable than it is. Madey, the orthopedic surgeon, said they’ve done tests that show that, even if placed directly on the skin, the WaveCel mesh wouldn’t break the skin under most impact forces. How does their new helmet work? According to a paper authored by Bottlang and Madey, helmets including the material reduced rotational acceleration from impacts by 73 percent compared to a normal helmet. A slip pad within a normal helmet (MIPS) only dropped acceleration by 22 percent, which seems like a substantial difference.
of this story at Slashdot.