Having your phone or tablet die on you when you are in the middle of a call or when playing your favourite online casino game is frustrating to say the least. While there have been many breakthroughs in mobile technology, even the most advanced mobile device needs to be charged every day or two with normal use.
This can be an issue if you are out and about and have no access to a wall charger. While portable power banks certainly have helped, these secondary battery devices need to be charged themselves and have to be lugged with you wherever you can go. The way forward seems to be a device that can charge itself while you use it.
Charging by Body Heat
This technology may not be as farfetched as you think. Researchers at the Massachusetts Institute of Technology may just have found a way to use body heat to charge your phone. The development team has created a button sized self-charging battery that has the ability to scavenge energy from low temperature heat sources, such as the human body.
According to the researchers, the device can charge itself at any temperature between 20°C and 60°C. This is a breakthrough, in that most heat charging devices require much higher temperatures. Designed by Dr Gang Chen and his research team, the self-charging battery could lead to the introduction of mobile phone batteries that would be able to be charged without having to be plugged into wall charger. This means you’d never have to stop playing online slots or other favourite casino games simply because the warmth from your hand could charge your battery.
The self-charging device is 2 centimetres wide and works by harvesting energy using the thermally regenerative electrochemical cycle. What this means is that the battery can actually produce more electricity at lower temperatures than what was originally used to charge it in the first place because of the energy absorbed by the body or external heat sources.
This process is then used to create a “heat engine” which generates electricity from the heat surrounding the battery. Previously, this process required a temperature difference of 50°C. However, the research team was able to tune the batteries electrodes to accomplish this with much lower temperature differentiations.
Charging Through Kinetic Energy
In China, a separate research team has come up with another answer to the dying phone problem. Researchers at the Chinese Academy of Science (CAS) along with the team at the University of Buffalo and the Institute of Semiconductors (IoP) have hit an idea to charge mobile devices using kinetic energy. Simply put, they have created a device that will charge your phone with the simple movements of your body.
What the team has invented is a gold-laced device that can generate electricity with even the smallest movements. This nifty device, which has been dubbed a triboelectric nanogenerator or TENG for short, was first described in a paper published in the journal Nano Energy. The device itself consists of two thin strips of gold that are separated by a strip of polydimethylsiloxane. This is the same semi-conductor substance that is used to make silicone lenses.
The way the device works is quite ingenious. One of the two strips of gold is stretched out so that when it is released, it crumples to create ridges. When the device is moved or bent, the friction is created between the gold layers and the strip in-between. Using a process called the triboelectric effect, electricity is created. When the bending and movement of the device causes electrons to flow between the two gold layers and produce energy. The more movement, the more the electrons move and the more energy is produced.
While this is not the first device to use the triboelectric effect to produce electricity, it is currently the only device to overcome the cost factor the ability to be produced in mass quantities. At just 1.5cm long the device can produce a max voltage of 124 volts at a current of 10 micro amps, which is more than enough to charge a smartphone.
While both devices are still in the testing phase it seems to be just a matter of time before the technology hits the mobile market. It is possible that mobile phone manufacturers will opt for the most efficient option, or the one that is cheaper to produce on a mass scale. In any case, we can expect to see self-charging smartphones and mobile devices on the shelves within the next few years.