The scientists of Korea Advanced Institute of Science and Technology (KAIST) have devised new technology which generates electricity from body heat, allowing you to charge electronic devices on the go
A team of KAIST researchers headed by Byung Jin Cho, a professor of electrical engineering, proposed the technology by developing a glass fabric-based thermoelectric (TE) generator that is extremely light and flexible and produces electricity from the heat of the human body.
In fact, it is so flexible that the allowable bending radius of the generator is as low as 20 mm. There are no changes in performance even if the generator bends upward and downward for up to 120 cycles.
To date, two types of TE generators have been developed based either on organic or inorganic materials. The organic-based TE generators use polymers that are highly flexible and compatible with human skin, ideal for wearable electronics. The polymers, however, have a low power output. Inorganic-based TE generators produce a high electrical energy, but they are heavy, rigid, and bulky.
Professor Cho came up with a new concept and design technique to build a flexible TE generator that minimizes thermal energy loss but maximizes power output. TE materials are printed onto a glass fabric by applying a screen printing technique. The pastes permeated through the meshes of the fabric and formed films of TE materials in a range of thickness of several hundreds of microns. As a result, hundreds of TE material dots (in combination of n and p types) were printed and well arranged on a specific area of the glass fabric.
When using KAIST's TE generator (with a size of 10 cm x 10 cm) for a wearable wristband device, it will produce around 40 mW electric power based on the temperature difference of 31 °F between human skin and the surrounding air.
Since the power consumption of the mobile device are high compared to electrical sensors,it is not practical to power the smartphone solely with this technology but it can be used as an assistance to battery ,so that you can extent your battery life with out sacrificing smart phone performance.
Professor Cho says the application of the new generator can be further extended to scale-up systems such as automobiles, factories, aircrafts, and vessels where we see abundant thermal energy being wasted which could be a great step towards the the green energy concept.
We expect to see this technology adopted to the wearable device and smartphones soon which will open a new era of green energy.