A waterproof keyboard printed on paper

Scientists have developed a new printing process that turns almost any paper or cardboard into a waterproof keyboard. You can fold it up and put it in your pocket and use it without electricity.

The technology uses a special coating which is liquid-proof and dust-resistant, allowing multiple circuit layers to be printed on paper without any smudges between them.

Then, on the other side of the paper or cardboard, it uses standard ink printing to indicate the pressure point (button). The circuit layer can meet the needs of any general keyboard, from the numeric keypad to volume control.

A printed paper keyboard requires no electricity. On the surface the devices called tribological nanogenerators or TENG can be fully powered by the touch of a finger.

Ramses Martinez, a biomedical engineer at Purdue University said, “This is the first self-powered electronic device that is entirely paper-based. We have developed a method to coat paper with highly fluorinated molecules to make it waterproof, oil-resistant, and dust-resistant. This oleophobic coating allows us to print multiple layers of circuits on paper without causing ink stains and ruining the circuits.”

When the printed parts of the paper are pressed down, they can transmit signals via Bluetooth to other devices, such as laptops. Then we have a light, foldable keyboard that can be placed anywhere and easily cleaned when necessary.

The technology is useful: the scale can be expanded easily using existing production processes, and it is environment friendly (paper can be recycled easily), flexible -- waterproof and fully customized.

Production costs are also cheap, less than 0.25 per unit, the researchers said. Potential utilities include intelligent packaging or occasions that require temporary input.

The research has been published in the journal “Nano Energy”.