Not quite sintered armorgel but...

[andygates]

Behold the Ribcap, a hat or helmet-liner made with something called d3o, a responsive material which is flexible normally but goes rigid and energy-absorbing on impact (website - wikipedia).  This is a goofy tank helmet liner one from Streetgadgets which made me think of Tank ravenbait, smokin' a fag and smashing beer bottles over her head just because.

Could it mean the death of the bike helmet as oldschool cotton caps get techno?  I'd love to think so.