Modern helmet construction hasn't changed significantly since the adoption of styrofoam impact absorption in the 1960s. (βλέπε φελιζόλ)
But new materials (βλέπε koroyd) and construction methods are improving safety, in some cases absorbing 30 percent more energy than their styrofoam equivalents. And you can buy helmets made from them today.
http://indefinitelywild.gizmodo.com/helmet-safety-is-being-revolutionized-right-now-1692246906