A Korean research team has developed a thermoelectric element that uses human body temperature to generate electricity and power wearable devices or the Internet of Things (IoT).
The Electronics and Telecommunications Research Institute (ETRI) announced on Jan. 15 it has developed a thermoelectric complex module that generates electricity using human body heat. The module, which is 5 cm in width and 11 cm in length, can convert the body heat energy into electricity and amplify it to power wearable devices.
When a patch-like structure is attached to the skin, a temperature difference occurs between the skin and the structure, and the sweat glands-like structure maximizes the energy efficiency. This core technology is called “biomimetic heat sink.” It increases the output of the thermoelectric element by five times that of conventional products.
In addition, the device also incorporates the power management circuit technology that keeps efficiency above 80 percent even at low voltages and converts it to a chargeable voltage.
In particular, the research team succeeded in generating a 35 microwatts(㎼) output, which is 1.5 fold higher than the 20 ㎼output previously developed by U.S. researchers. In addition, it has been confirmed that when the six devices are modularized in a bundle, they can continuously generate energy from the human body temperature up to a commercialization level of two to three milliwatts (㎽).
In fact, the research team succeeded in amplifying the voltage by attaching six patches to the wrist of an adult, lighting the letters "ETRI" on the LED display board using the body temperature of the person without using a battery.
In addition, a dry adhesion method that utilizes nano hierarchical structure was used to attach to the skin contact area in a natural form, and for the outer part of the module, micro hierarchical structure was used to prevent easy tearing. It was developed in a micro- and nano-hybrid structure for stability and convenience.
The research team is currently carrying out a follow-up study to implement the power management circuit in one chip to improve the aesthetics and wearability in a moving situation while decreasing the discomfort of wearing patches. The team predicts the technology to be commercialized in two to three years.
"When thermoelectric devices are commercialized, they can be used to power wearable devices or IoT and for hardware platforms and provide new services such as digital healthcare, smart home, and smart city," said head of ETRI ICT materials and components research group.