Stop the Green Dream presses. Julian Melchiorri has built a leaf that absorbs CO2 and sunlight and produces oxygen. Rather than just growing a plant like most of us who want leaves in our lives, Melchiorri's work got positively semi-scientific. By breaking down the tough proteins in silk, and plucking out useful chloroplasts from plant matter, the end product "lives" on light and water, and produces what we breathe. Produced as a part of the Royal College of Art course "Innovation Design Engineering," the Silk Leaf project was conceived as a way to manage emissions and neutralize environmental impact with a space efficient, "biological" material.
The Silk Leaf is a very thin membrane of silk protein, covered with a solution of chloroplast, resulting in a very thin, flat, seaweed-looking material. Lightweight, flexible, and made from growable materials, it sounds like a cool class project if nothing else. It's unclear whether the use of silk and the apparent destruction of living plants would be hurdles barring further development. Silk isn't exactly known for its affordability, and there's no explicit description available of the chloroplast extraction process. However, high tensile protein production has been investigated before (remember the Spider Goats?) and overall the idea is a good one with interesting potential applications.
Molecules! Gloves! Science!
Melchiorri suggests the material could be used on the outside of buildings as a city air scrubber. He also thinks these breathing "leaves" could be used within closed systems, like space ships or stations, where keeping the air supply balanced and breathable requires mechanically intensive processes. As he helpfully points out, "Plants don't grow in zero gravity." Nope, they sure don't... unless they're happily growing on the ISS.