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.


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Source: *FS – All – Science News 2 Net
Science and Bicycling Meet In a New Helmet Design