Smartphones and tablets are wonderful but their batteries don't last so long. You know the feeling - you notice the battery is low and that you forgot the power chord at home or at work and in a few minutes you'll be cut off. It generally happens just when you're expecting a call or need to access information. Unless we can develop batteries with much better capacity we're going to have to find new ways to recharge them.
Hope is at hand. According to a new BBC article we may soon be able to charge our mobile batteries by simply walking (Mobile phones could soon be 'powered by walking'). It seems that around 20 watts of power is lost as heat as we walk and the aim is to capture that energy and put it to better use. A device placed in your shoe generates energy by kinetic charging. Walking sets micro droplets in motion in the device and this is converted into enough energy to charge a mobile. Scientists at the University of Wisconsin have developed this technology and have recently published a study in the journal Nature Communications (Reverse electrowetting as a new approach to high-power energy harvesting, T Krupenkin, A Ashley Taylor).
"The new personal mechanism uses a principle known as "reverse electrowetting" - converting the energy of moving microscopic liquid droplets into an electrical current. Once placed in a shoe, the device - which consists of thousands of these electrically conductive droplets - is able to generate electrical energy. There is enough power, according to the researchers, to charge a standard mobile phone or laptop."
They have now formed a company, InStep NanoPower, to further develop this technology into a commercial proposition.The first problem is to transmit the power from the shoe to your mobile or laptop; a wire would be somewhat clumsy. According to the company web site the power can be transmitted wirelessly.
I look forward to this technology to put an end to searching for all those annoying power cables (every device has its own unique solution of course). Very soon you'll see people in the park taking their laptops for a brisk walk.