Wearable Thermoelectric Nanogenerator Based on Carbon Nanotube for Energy Harvesting

Wearable and portable devices are appearing prominently in consumer electronics over the last decade and are becoming inevitable in this modern era. However, powering and recharging these devices are still tremendous challenges. Here, we designed thermoelectric nanogenerators and a novel textile based thermoelectric energy harvester based on carbon nanotube (CNT) which can be solution to the problem. These energy harvesters can harness solar or thermal energy to generate electricity. The reason for preferring textile based thermoelectric generator is that it can be used ubiquitously and can be used to power up wearable devices whenever needed. CNT is selected as the material of choice due to extreme tensile strength of CNTs so that long fibers required for textile can be manufactured with it and extraordinary tunability of electrical and thermal properties of CNTs. Though, some other thermoelectric materials like Bi ₂ Te ₃ and PbTe have greater Seebeck coefficient than that of CNT, their tensile strength is much smaller and they are toxic. In our textile based energy harvester, the CNT fibers are incorporated with conventional textile fibers like cotton. We proposed different configurations of textile based energy harvester and corresponding generated thermoelectric voltage was estimated. In series configuration, we found voltage of 55.2 μV for 1 K temperature difference in a 44 mm long fiber.