"Highly porous hierarchical structure of a Coscinodiscus oculus-iridis (Ehrenberg 1840) diatom shell."
Pavel.Somov, CC BY-SA 4.0, via Wikimedia Commons.
"Highly porous hierarchical structure of a Coscinodiscus oculus-iridis (Ehrenberg 1840) diatom shell."
Pavel.Somov, CC BY-SA 4.0, via Wikimedia Commons.