The same elements that keep humans alive—water and air—could one day also be used to entertain us while we laze about on the couch. Because researchers at Aalto University in Finland have created a unique display technology that uses just air and H20, instead of LCDs or LEDs.

The secret is a multi-level superhydrophobic surface that repels water and traps air, and was inspired by the extreme waterproof properties of the lotus leaf. The surface is actually covered with tiny posts, just ten micrometers in size, that are each covered with even smaller nanofilaments. Using a precision nozzle that doubles as a printing head, the researchers are able to switch the surface between wet and dry, even though it's submerged underwater the entire time. And as a result, they're able to write, and re-write, complex designs and images like an inkjet printer does. Minus the atrocious price of ink, that is. [PNAS via Gizmag]