Alternative sources of energy that power devices may also include humans.
If you ever talk to people dealing with the mystical world, they will tell you about aura and the power of the human energy field. You would know about negative and positive energies, and how one can balance the energy around them to create a better world. While the mystical world has been all about harnessing that energy and creating a better life, increasingly scientists are also working on how humans can harness this power. With the demand for devices growing and no way to keep up with the battery problems, there have been attempts to use humans as an alternative source to keep devices powered. Science can still not turn you into one of the comic superheroes, where you can charge your house or power an AC. But given the rate of progress, human energy can certainly translate into more power for wearables. Body heat If you can get the mercury to shoot up and ice to melt, powering devices should not be a problem. For years, institutes have been working on creating power from slight body temperature variations. That does not mean you have to get a fever to charge your Fitbit. Research conducted by Daryoosh Vashaee of the North Carolina State University and his team shows a temperature difference of less than one degree can be harnessed to create energy to power devices. Published in the journal Applied Energy, the research points that although it is easy to store this energy, and it can come in the form of a wearable, the problem is it can only generate microwatts of power, which cannot even power up a fitness tracker. More important, much like any other energy source, it loses power when idle. Although a bigger generator can create more power, who would want to wear a clunky device to keep their gadgets charged?
Vashaee does highlight this to be a big drawback; he says efficiency is the key. Output for such devices may increase given the technology, but scientists have to ensure there is no loss of power in the idle state. The real application of such devices is not for wearables but for biomedical research. A team of scientists at the University of Utah have developed a much similar device, which they believe can be instrumental in powering a pacemaker or an insulin pump. If possible, pacemakers would be able to run for decades without needing a replacement, reducing the risk of infection that goes with replacing a pacemaker. Walking If body heat sounds too bizarre, walking is something that you can wrap your heads around. An easy concept to understand is that motion generates energy and companies have been successful in implementing this. In 2013, a company called SolePower started a project on Kickstarter, where an anklet-like device could derive power from walking. The company claimed that it could power a dead iPhone with 2.5-5 miles of walk.
Recently, the company announced a smart boot, which would send GPS location and also generate power to recharge cells. It claims that people can get an hour of talk time with each hour of walking. Clearly, the technology is not for the lazy. But that does not mean scientists are not venturing into bizarre notions in this field. Vanderbilt University in the US has created an ultrathin layer of wearable, which, they believe, can generate energy both from walking and waving. While it cannot do what SolePower is doing as the amount of energy is very little, the takeaway is that it can be built into clothes and create smart clothing. The thin layer can create shirts fitted with LED that can change colour or one that can record movements and incorporate them into virtual technology. Breathing Breathing cannot power your wearables, but it can help extend the battery life of biomedical devices.
Research on biofuel cells has been on for long—these can generate electricity from blood sugar—and researchers from the University of Wisconsin-Madison have been improving the efficiency of a device that can create enough energy to power biomedical devices for breathing. The device or belt made of piezoelectric material, polyvinylidene fluoride (PVDF), can tap airflow caused by human respiration to create vibrations, which, in turn, creates energy. Similar amounts of energy can also be generated from friction, where a smart skin attached to your body creates enough friction to generate millivolts of power. As batteries become more of a problem than a solution—blasts of Samsung Note 7 devices is the best example of this problem, where battery optimisation led to faulty batteries—there is a need to look at alternative sources. And until we cannot solve that problem, we cannot advance the field of wearables. Human energy, thus, seems promising. But the best we can do for now is walk and expect that, over time, even the lazy ones will get to recharge their batteries.