A team of scientists working at the Huazhong University of Science and Technology recently created a wearable and adjustable thermocell based on two different types of gel electrolytes that are capable of harnessing body heat. These can abstract a small portion of your body heat to empower wearable electronics. The makers were able to generate power worth 0.7V as well as 0.3mW at a temperature of 5 degree Centigrade.
As per these researchers, the temperature difference between surroundings and skin, it is not easy to use body heat for empowering devices and instruments. The thermoelectric generators that were used for semiconductors till now were actually of little use because they could convert very less heat into power. These were expensive and very brittle with respect to wearable systems, it is one of the prime reasons why these were discarded. Thermocells, on the other hand, are electrolyte solutions that are very complicated in terms of integration when it comes to extensive wearable electronics.
A solution for this problem was recently given by the team with gel-electrolyte based thermocells. The scientists have fused two kinds of cells that have two varieties of redox pairs. Every single cell consists of two metal plates that behave as electrodes along with an electrolyte gel between them. The first cell has been provided with a Fe2+/Fe3+ redox pair while the second one has some complex ions. The cold of cell one gives negative potential while the same of cell 2 gives positive potential.
These two cells have been arranged in form of checker board by the researchers. The cells get connected with each other through metal plates that alternate below and above the surface. These were then integrated into a glove. Whenever the glove is adorned by the user, the required temperature difference is obtained between upper and below plate. This leads to production of voltage between the two cells that generates current for empowering or charging a battery.