01 June 2016
A New Take On Invisible Ink: Living Ink
In an effort to create and develop a sustainable algae ink to replace regular printer ink, two brilliant scientists came across something super cool. After studying and researching algae for the past 10 years, they discovered that it can be used as a kind of “living ink” that uses sunlight and CO2 to reveal itself.
It’s kind of like that science project you did when you were a kid where you mixed lemon juice with water, let your message dry and then revealed it under light...but this is WAY better.
See the science behind the lemon juice invisible ink experiment is essentially that the acidity in the lemon juice weakens the paper. The acid remains within the fibres of the paper after the juice has dried and when the paper is held against heat, the acidic parts of the paper turn brown or burn – revealing the message. (For an actual scientific explanation and instructions for how to do the experiment check out this Scientific American article: Invisible Ink Reveals Cool Chemistry.)
But with Living Ink which contains algae and cyanobacteria – the message you write actually grows by harvesting light energy and consuming CO2. It’s a time-lapse bio ink! The algae and cyanobacteria reproduce cells at an exponential rate, i.e. 1 cell becomes 2, 2 become 4, 4 become 8 and so on. And in this way, your “invisible ink” reveals itself because it actually grows to reveal the message after several days of exposure to sunlight and turning carbon dioxide into increased biomass and oxygen. Crazy stuff, right?