Ling Li looks to sea urchins for stronger ceramic foams

https://vtx.vt.edu/articles/2022/10/eng-ling-li-urchins.html

"structure of sea urchin spines...  interconnected short branches... damage tolerance... balance between number of nodes and branches... nodes with too many connected branches cause structure to become brittle... connected to three branches... bending-induced fracture instead of catastrophic stretching-induced fracture...  gaps slightly smaller than size of branches... once fracture, can be locked in place immediately by smaller openings. Broken branches stack on top of one another creating dense region sustain load"