This journey began with the SMOG FREE RING. It is a cool concept by the Dutch design studio Roosegaarde. The idea behind each ring is that inside of the transparent cube there's a blob of condensed smog, which is collected via outdoor air filters. The profits from the sales of such cubes are reinvested in order to create more of such filtering machines.
I liked the concept a lot, but the kind of ring they make to put this cubes on isn't exactly my style... Therefore I decided to buy only the cube and 3D-print the ring of my own design. In this specific case, my own design would imply heavy use of the somewhat cliché Voronoi-tesselated mesh, which is not easily doable outside of the scope of additive manufacturing.