Now you see it, now you dont!
Natural phenomena provide the inspiration for many ideas. Japanese researchers have recently managed to get a specially coloured gel to turn transparent faster than the blink of an eye. Their inspiration has come from the octopus.
Octopus skin contains tiny ink sacs that octopi use to mix their own personal camouflage colour. When the muscles in the skin contract, the sacs become so tightly compacted that the ink inside them turns invisible. When the sacs expand again, the colour returns.
Now researchers have found a way to imitate this behaviour. The gel they have made is composed of the world's tiniest ink sacs, which they fill with colour. Then they heat the whole thing to 34 degrees Celsius and, voila, the sacs shrink to one-tenth their original size, just like in the skin of the octopus. The ink is compacted so tightly that it becomes invisible.
In future, it might be possible to make a gel that reacts to light, electricity or toxins, and to spread it on panes of glass and on buttons and knobs. That would make it possible to make windows that change from coloured to transparent, for example. Or possibly to make measuring equipment that would turn bright red in the presence of a toxin. Smart or what?
Translation: Linda Sivesind