Achieving High Thermoelectric, Stretchable, and Self-Healing Capabilities in Self-Supported PEDOT:PSS/Nafion/Poly(vinyl Alcohol) Composites for Wearable Thermoelectric Power Generators and Sensors

In wearable devices, the escalating demand for self-powered and low-maintenance cost energy has emphatically underscored the significance of organic thermoelectric materials (OTMs). Nevertheless, a widespread challenge is that most high-performance OTMs are prone to damage, which significantly hampers their reliability and longevity. This study presents a flexible and self-healing thermoelectric composite comprising poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/Nafion/poly(vinyl alcohol) (PVA) and explores its application in self-powered strain and sensors. The results reveal that the self-healing thermoelectric material showcases impressive flexibility, with a tensile strain capacity of 141% and a peak tensile strength of 26 MPa. Notably, it demonstrates superior thermoelectric performance, featuring a remarkable conductivity of 424.14 ± 34.28 S·cm–1, the peak value reported thus far for self-healing and stretchable all-organic thermoelectric materials, along with a notable power factor of 8.70 ± 0.81 μW·m–1·K–2. The dynamic interplay of hydrogen bonding among PEDOT:PSS, Nafion, and PVA facilitates swift and effective repair of scratches and cuts, sustaining 76.1% of the initial thermoelectric performance. Furthermore, utilizing the composite, a thermoelectric generator was assembled with a power output of 120.64 nW at a temperature difference of 36 K. In addition, sensitive self-powered strain and temperature sensors were successfully developed. This work introduces an effective method for achieving intrinsic self-healing in OTMs, resulting in enhanced electrical conductivity and power generation capabilities.