Turning soot into ink, algae into lighting, and other green ideas

Your printer cartridges and air pollution have something in common: carbon. The black particles emitted from burning fossil fuels make good pigment. That’s why a start-up in India makes Air-Ink, turning exhaust harvested from diesel generators into ink for uses from art to packaging. Computer giant Dell is eyeing the sooty brew for printing its product boxes. —Christina Nunez

In the eclectic collection of the Victoria and Albert, the museum of art and design in London, only one object—out of more than 2.3 million—is alive: a chandelier. The fixture not only provides light but also absorbs light and purifies the air in the room. Hanging from the chandelier’s metal branches are 70 veined, synthetic pouches, “leaves” made green by the millions of algal microorganisms inside. The algae take in light from LEDs and the sun, and carbon dioxide from the air; when that mixes with water and nutrients circulating in the leaves, oxygen is produced. In short: This chandelier performs photosynthesis. When museumgoers visit the artwork, titled “Exhale,” breathing becomes a reciprocal activity: They breathe out CO2, which the algae replace with oxygen.

“Exhale” was devised by engineer-inventor Julian Melchiorri and his company, Arborea. The start-up is developing technologies to industrialize photosynthesis for use in a sustainable food system, as well as to fight climate change and pollution. Melchiorri says algae work so well in these applications that they soon could be in wider use: in “biosolar” panels on buildings’ rooftops, and even in spaceships and space colonies. —Hicks Wogan