Researchers at Purdue University in the US developed technology to turn cardboard and paper into interactive interfaces, thanks to an omniphobic coating.

The engineer developed a simple printing process that renders any paper or cardboard packaging into a keyboard, keypad or “other easy-to-use human-machine interfaces”. The coating, based on highly fluorinated molecules, makes paper relent to water, oil and dust. In turn, this makes it possible to print multiple layers of circuits onto the paper without smearing the ink in the process.

The innovation facilitates the fabrication of vertical pressure sensors that do not require any external battery, as they harvest energy from contact with the user.

The technology is compatible with conventional large-scale printing processes. According to the researchers, it could be implemented to convert conventional cardboard packaging or paper into smart packaging or smart human-machine interface. For instance, it could be used to verify if the food inside the packaging is still safe to be consumed, or to sign for a package on the actual package. Even simple paper sheets from a notebook can be transformed into. A music player interfaces for user to choose songs, play them and change their volume.

Photo: Purdue University