High-Performance Stretchable Thermoelectric Generator for Self-Powered Wearable Electronics.

Wearable thermoelectric generators (TEGs), which can convert human body heat to electricity, provide a promising solution for self-powered wearable electronics. However, their power densities still need to be improved aiming at broad practical applications. Here, a stretchable TEG that achieves comfortable wearability and outstanding output performance simultaneously is reported. When worn on the forehead at an ambient temperature of 15 °C, the stretchable TEG exhibits excellent power densities with a maximum value of 13.8 µW cm-2 under the breezeless condition, and even as high as 71.8 µW cm-2 at an air speed of 2 m s-1 , being one of the highest values for wearable TEGs. Furthermore, this study demonstrates that this stretchable TEG can effectively power a commercial light-emitting diode and stably drive an electrocardiogram module in real-time without the assistance of any additional power supply. These results highlight the great potential of these stretchable TEGs for power generation applications.

High-Power-Density Wearable Thermoelectric Generators for Human Body Heat Harvesting.

Wearable thermoelectrics has attracted significant interest in recent years. Among them, rigid-structure thermoelectric generators (TEGs) were seldomly employed for wearable applications, although those exhibit significant advantages of high device output performance and impact resistance. Here, we report a type of rigid wearable TEGs (w-TEGs) without ceramic substrates made using a simple cutting-and-bonding method. Owing to the small contact area, the w-TEGs comprising 48-n/p-pairs can be well attached to the human body. The lack of ceramic substrates leaves more space in the height direction, which benefits the wearability in practical applications and high power density. We demonstrated that increasing the height of w-TEGs from 1.38 to 3.14 mm significantly improves the power density by a factor of 10. As a result, the maximum power densities of 7.9 µW cm-2 and 43.6 µW cm-2 for the w-TEGs were realized under the breezeless condition and a wind speed for normal walking, respectively. This work provides a feasible design solution for rigid-structure free-substrate w-TEGs with very high power density, which will speed up the research of wearable thermoelectrics.

Poly(3,4-ethylenedioxythiophene)/Te/Single-Walled Carbon Nanotube Composites with High Thermoelectric Performance Promoted by Electropolymerization.

Electrochemical polymerization has proven very effective in fabricating flexible organic/inorganic composite films with high thermoelectric (TE) performance. In this work, dynamic three-phase interfacial electropolymerization of 3,4-ethylenedioxythiophene (EDOT) combined with physical mixing of single-walled carbon nanotubes (SWCNT) and tellurium nanowires was employed to prepare PEDOT/Te/SWCNT thermoelectric composites. When the loadings of Te and SWCNT were changed, the electropolymerized PEDOT exhibited great capability of improving TE properties of the resultant composites with a highest electrical conductivity (σ) of 900.3 ± 20.5 S cm-1 and Seebeck coefficient (S) of 43.4 ± 0.6 µV K-1, affording maximum power factor (PF) of 169.8 ± 7.8 µW m-1 K-2 at room temperature.