Three organic thermoelectric materials systems: doped conjugated polymer-based thermoelectrics, nanomaterials thermoelectrics, and ionic thermoelectrics.
In a major step toward sustainable energy, a team of researchers from National Taiwan University (NTU), led by Professor Cheng-Liang Liu of Department of Materials Science and Engineering, has developed novel organic thermoelectric materials and devices. These materials convert waste heat, including body heat, into usable electrical energy. Their work offers exciting potential for wearable technology, where lightweight and flexible devices can power sensors using the heat from our bodies.
Thermoelectric materials generate electricity from temperature differences using the Seebeck effect. While traditional materials have limitations like being rigid, toxic, and only functioning at high temperatures, Professor Liu’s team has made groundbreaking improvements with organic and polymeric materials. These advances have already been applied in areas like low-grade waste heat recovery (below 100 °C) and wearable devices, which can work at low temperatures, making them practical for household appliances and wearable thermoelectric devices in daily use.
The team of Professor Liu’s research focuses on three major thermoelectric materials systems:
1. Doped Conjugated Polymers-based Thermoelectrics:
By fine-tuning the molecular structure of polymer materials, the team significantly boosted the electrical conductivity of these thermoelectric materials. This led to a power factor (a measure of efficiency) of 22.4 mW m⁻1 K⁻2. This innovation was published in Journal of Materials Chemistry A in 2024 (page 9806-9816).
2. Nanocomposite-based Thermoelectrics:
The team combined low-thermal-conductivity polymers with highly conductive carbon nanotubes, achieving a more efficient n-type thermoelectric device with a zT value of 0.13. Their work was published in Advanced Functional Materials in 2024 (page 2406165).
3. Ionic Thermoelectrics:
Using a unique system with redox couples and gelatin-based hydrogels, the team created a device with a high Seebeck coefficient of 21.6 mV K⁻1. With just a 9 °C temperature difference, the device powered a 1.5 V LED without external voltage-boosting convertor. This research was featured in Materials Today Energy in 2024 (page 101546).
Looking ahead, Professor Liu’s team plans to continue refining these materials and processes to improve efficiency and develop thermoelectric modules specifically designed for wearable devices. Their research holds great promise for creating self-powered wearable technology and enhancing energy recovery from low-grade heat.
Corresponding author’s email address: [email protected]
References:
Journal of Materials Chemistry A
https://pubs.rsc.org/en/content/articlelanding/2024/ta/d4ta00032c
Advanced Functional Materials
https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202406165
Materials Today Energy
https://www.sciencedirect.com/science/article/pii/S2468606924000583
