We recently took a look at the ongoing research around how to improve the supply of power the devices in remote places that will be hooked up to the internet of things. We discovered that engineers at the University of Washington are in the process of designing a new system which uses radio frequency signals as a power source and reuses existing WiFi infrastructure to provide the connectivity. This is far from being the only unique way to power next generation devices, however. Another problem that needed a solution was how to keep a sufficient charge in the batteries of wearable tech; now a Korean research team might just have the answer.
Led by Cho Byung-Jin, Professor of the Division of Electrical Engineering at KAIST, the team has developed a new technology that powers wearable devices using nothing more than body heat. The technology works by developing a thermoelectric module that can convert body heat into electricity using glass fabric.
Firstly a thick paste is created by grinding n-type and p-type semiconductor materials into a powder and then mixing them together along with a special solvent. This paste is then screen printed onto a glass fabric as dots. The dots themselves are a mere 1.5mm in diameter and a near-invisible 500um (microns) thick – resulting in a very impressive piece of engineering. Once constructed, the thermoelectric module was estimated to be fourteen times more efficient than a traditional ceramic substrate in terms of it’s electric production capabilities – as well as being considerably lighter.
If the new device was a 10cm x 10cm band worn around a typical person’s arm, it would have the ability to produce approximately forty milliwatts of electricity at twenty degrees Celsius – comfortably enough to power a semiconductor chip. If the device was expanded to 50cm x 100cm and was worn on a person’s torso it would be able to produce two watts of electricity – enough to fully charge a modern smartphone.
Professor Cho explained, “The biggest obstacle to the commercialization of wearable devices is related to problems with power supplies. So, a battery of any wearable device is required to be frequently replaced at the moment. And the battery itself is heavy. However, it is now possible to utilize wearable devices semi-permanently using this thermoelectric module, because it generates electricity with body temperature”.
He went on to add that he believes that the new technology’s biggest selling point was that unlike conventional organic-based thermoelectric module, this one could be produce on a large scale for minimal cost. Furthermore, he hopes that in the future it could also be utilised in tasks such as converting wasted heat from cars, factories, aeroplanes, and ships into electricity.
Is wearing a rechargable battery on your body the answer to the problem of supply power to wearable tech? Would you consider wearing a 50cm x 100cm device just to charge a phone?
By Daniel Price
