Shellmet helmet is made of scallop shells – plus it looks like one

Utilizing a process developed by Prof. Hiroshi Uyama from Osaka University, the shells are first boiled and sterilized, then pulverized and rendered into calcium carbonate powder, which is mixed with powdered discarded plastic and rendered into pellets. Those "Shellstic" bioplastic pellets are subsequently poured into a helmet mold and heated, causing them to melt.

Once the bioplastic has cooled and hardened, the result is a helmet with a scallop-shell-inspired ribbed design. That design, along with the inclusion of the calcium carbonate, is claimed to make the helmet about 33% stronger than it would be otherwise. Additionally, the production process is said to generate approximately 36% fewer greenhouse gas emissions than if 100% virgin plastic were used.