This ‘smart’ self-cleaning keyboard is powered by you

The bonus: It works for its owner and no one else

 

 

Rob Felt, Georgia Institute of Technology

 

A new keyboard can tell if you’re its owner. It locks out anyone else, even if that person knows your password. What’s more, this device needs no batteries. It harvests all the energy it needs from the action of your typing.

 

All in all, “This will hugely improve the security of a computer,” predicts Zhong Lin Wang. He’s a materials scientist at the Georgia Institute of Technology in Atlanta and a co-designer of the new keyboard.

 

“Our fingertips have electrostatic charges,” explains Wang. That means there’s an imbalance of electrons. Your fingertips generally have a slight positive charge. So they have somewhat fewer electrons than the area around them. And that principle makes it possible for typing to induce an electric current in the keyboard, Wang points out.

Just as the closely spaced bumps on a lotus leaf (shown here) repel water, the nanowires on the new keyboard’s keys repel dirt, oils and liquids.

stedenmi/iStockphoto

 

To understand how this works, consider a magnet. At one end is a positive charge. At the other is a negative charge. Opposite poles attract. So if you put the positive end of one magnet next to the negative one of another, they will latch onto each other. A similar idea applies to electrostatic charges. Positive charges attract negative ones.

Wang’s group put two layers of metal electrodes under the keyboard’s plastic surface. When a finger approaches a key, it attracts free electrons to the top electrode. The bottom electrode supplies them. As soon as the finger lifts off of the key, the electrons flow back to the lower electrode. Any flow of electrons creates an electric current.

 

And this induced electric current can power the keyboard — but only if the current is strong enough. To achieve that, the Georgia Tech team focused on nanotechnology.

 

(“Nano-“ refers to things measured on the scale of 100 billionths of a meter or less.)

 

The keys of the new keyboard are made of the same inexpensive plastic that might be found on any other standard keyboard. But instead of being smooth, the keys have millions of tiny plastic “nanowires” on their surface. Those nanowires make the new keys special. They add more surface area to every key, increasing the effective contact area between the plastic and the fingers, Wang explains. This ensures that there’s enough power to run the keyboard as someone types.

 

Because fingers touch the keys and then back off, that current isn’t constant. It also varies with the force and speed at which a typist strikes different keys. And that rate, force and pattern of typing will differ from one person to the next. In much the same way that a voiceprint gives a unique signature to the way each person speaks, typing will give a personal signature to each person’s keyboard use.

 

What this means, Wang explains, is that “even if the same phrase is typed by three different people, the [electrical] output signals are very different.” Thus, typing can be a type of biometrics — a way to identify people based on unique biological features.

 

The keyboard records information about the typing pattern and sends it to a program in the computer. The program then checks to see if the pattern matches the right user. If not, an alarm sounds, and the computer locks the typist out.

 

The new keyboard is also self-cleaning. All the tiny nanowires on the keys repel water, oils and dirt. It’s the same principle that lets a lotus flower float on a lake. The lotus has tiny water-repellant nanobumps covering its leaves.

 

Liming Dai is a polymer scientist who works with nanotechnology at Case Western Reserve University in Cleveland, Ohio. He did not work on the new keyboard, but he thinks the design could be important in getting better performance from a variety of devices.

 

“It could also be applied to a touch screen,” for instance, Dai says. Then smartphones and notepads could harvest energy from the motion of someone typing or drawing. And these devices could also benefit from the same keystroke “fingerprint” concept to keep strangers from using them. The smart keyboard might even be made from flexible polymers to create a medical sensor.

 

Future work might make the keyboard even more useful, Dai adds. A later design might build tiny capacitors onto the nanowires, he suggests. Capacitors are little devices that temporarily store an electric charge. Those might then power light-emitting diodes, or LEDs, to light a keyboard in the dark.

 

Meanwhile, Wang’s team has built a working prototype of its keyboard. If a company decides to fund its production, this keyboard could be in stores in as little as two years, says Wang.

 

His group published details on the design of its new keyboard in the January 27 issue of ACS Nano.

 

Fonte: https://student.societyforscience.org/article/%E2%80%98smart%E2%80%99-self-cleaning-keyboard-powered-you