Researchers at the Georgia Institute of Technology have developed an innovative keyboard that can accurately identify users based on their typing patterns. On top of that, the dirt- and water-resistant device can power itself by harvesting the static electricity on your fingertips.

Passwords have long been used to protect our sensitive data, but they can easily be stolen with potentially devastating effects. To provide an additional layer of security, phones and tablets have started incorporating biometric sensors like fingerprint scanners, and iris scanners may not be far behind.

Taking a different approach to biometric identification, a team of researchers led by Prof. Zhong Lin Wang at the Georgia Institute of Technology has developed a keyboard that can reliably identify users based on their unique typing patterns, such as the pressure applied to each key and the time spent between strokes.

Most keyboards operate on mechanical switches under each key that can only discriminate between two states, pressed or unpressed. The keyboard developed by Wang’s team, however, is built in a very different way.

Rather than relying on switches, this "intelligent keyboard" works by stacking four layers of transparent film on top of each other. Two layers of indium tin oxide act as the electrodes and are separated by a layer of PET plastic (the material we use to make water and soda bottles). On top of the electrodes, a layer of FEP plastic harvests the static charges in our skin as fingers touch and then leave each key, producing electricity via the triboelectric effect.

The keyboard stacks four transparent layers on top of each other to harvest and collect electricity from your fingertips (Image: Georgia Institute of Technology)

This unique structure allows the keyboard to register a complex electrical signal for each key punch: when processed and analyzed, the signals create patterns that serve as a distinctive signature for each user. To back up that claim, the scientists asked 104 subjects to type the word "touch" four times on their keyboard, and this small amount of data was enough to identify the typist with good accuracy. Coupling passwords with this new form of authentication could therefore make our data a lot more secure.

The plastic layered structure means the keyboard doesn’t just record keystrokes but can also harvest and store the static electricity in our fingertips. Although this is not a feature of the current prototype, that energy could be used to power a Bluetooth transmitter to make the keyboard wireless, or even to charge third-party low power devices.

Last but not least, the absence of moving parts and choice of materials makes this keyboard much easier to keep clean. "You could pour coffee on the keyboard, and it would not be damaged," said Wang. "Because it is based on a sheet of plastic, liquids will not hurt it."

As the keyboard is based on cheap materials that are common throughout the electronics industry, Wang and team believe their device will be competitive with existing keyboards in terms of both cost and durability.

A paper describing the advance appears in the journal ACS Nano.

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