Self‐Healable and Stretchable Organic Thermoelectric Materials: Electrically Percolated Polymer Nanowires Embedded in Thermoplastic Elastomer Matrix

• Published in: Advanced functional materials 2020-02, Vol.30 (9), p.n/a
• Main Authors: Jeong, Yong Jin, Jung, Jaemin, Suh, Eui Hyun, Yun, Dong‐Jin, Oh, Jong Gyu, Jang, Jaeyoung
• Format: Article
• Language: English
• Subjects: Composite materials; Damage; Electrical resistivity; Energy harvesting; Healing; Materials science; Mechanical properties; molecular doping; Nanowires; organic thermoelectric materials; Polymer matrix composites; polymer nanowires; Polymers; self‐healing and stretching properties; Stretchability; Thermal energy; Thermoelectric materials; Thermoplastic elastomers
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201905809

Self‐healable and stretchable energy‐harvesting materials can provide a new avenue for the realization of self‐powered wearable electronics, including electronic skins, whose main materials are required to be robust to and stable under external damage and severe mechanical stresses. However, thermoelectric (TE) materials showing both self‐healing properties and stretchability have not yet been demonstrated despite their great potential to harvest thermal energy in the human body. As most existing TE materials are either mechanically brittle or unrecoverable after being subjected to damage, a novel approach is necessary for designing such materials. Herein, self‐healable and stretchable TE materials based on all‐organic composite system wherein polymer semiconductor nanowires are p‐doped with a molecular dopant and embedded in a thermoplastic elastomer matrix are reported. The polymer nanowires are electrically percolated in the matrix, and the resulting composite materials exhibit good TE performance. The composites also exhibit both excellent self‐healing properties under mild heat and pressure conditions and good stretchability. It is believed that this work can be a cornerstone for the design of self‐healable and stretchable energy‐harvesting materials as it provides useful guidelines for imparting electrical conductivity to insulating thermoplastic elastomers, which typically possess versatile and useful mechanical properties. A novel conceptual approach for the realization of self‐healable and stretchable thermoelectric materials is reported. To meet these mechanical criteria, a thermoplastic elastomer is employed as the matrix of an all‐organic composite system in which p‐doped polymer nanowires are electrically percolated to impart thermoelectric properties. The thermoelectric composites exhibit excellent self‐healing and stretching properties under external damage and mechanical stresses.