The human body, generally, provides a low-heat flux, which requires thicker thermoelectric elements that typically need to be larger than an inch to generate a useful power output. However, by using woven semiconductor strings to replace conventional thermoelectric generators, higher power outputs are possible.
Kazuaki Yazawa, a research associate professor at Purdue University, said: “The only way to reduce the thickness of the module is by designing the thermoelectric generator using a weaving technique. This allows the technology to be very flexible and dense.
“Lengthening the threads and using a unique combination of insulation makes the generator more flat and manageable, which makes it ideal for use in clothing or any shape that can be wrapped in a flexible fabric that has waste heat such as a chimney or even a coffee cup.
“Additionally, these semiconductor strings harness the maximum amount of heat from the body or other ambient heat sources, providing reliable power for [portable electric devices]… eliminating the need for batteries.”
The technology could greatly benefit tech wearables like those in the medical and healthcare industry including heart monitors, respiration and perspiration monitors. There is also a huge market for wearables in sports to optimise human performance.
Yazawa said: “If you have a patient or an athlete who is overheating, real-time information of their vitals could be used by coaches and medical professionals to better monitor and treat their players or patients. These types of devices need energy to be actively charged so they can be used continually.”
The technology could also be used to provide a cooling effect for professional athletes, fireman or even military personal.