Researchers at the Lawrence Livermore National Laboratory are working on 18-month study in collaboration with Autodesk Research, a 3-D design software company, to design the helmet that can prevent brain injuries suffered in sports. Experimenting on different materials for the Helmet, Silicone seems to be perfect for foam pads while they will continue to patent new discovering during the on-going project.
Source: https://mic.com/articles/136528/3-d-printed-helmets-prevent-concussions#.I1qcUbqQt