Self-Adhesive and Stretchable Conducting Polymer Blends

Self-adhesive and stretchable conducting polymer blends can have important applications in many areas, particularly wearable electronics and bioelectronics. For example, they can be used as conformal dry electrodes to continuously detect epidermal biopotential signals for the long-term. Although the blends of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS), water-borne polyurethane (WPU), and d-sorbitol (SOR) can exhibit high mechanical stretchability and good self-adhesiveness to skin, the mechanism for their self-adhesiveness is not clear because none of the components is self-adhesive individually. Here, the mechanism for the self-adhesiveness is revealed by investigating the structure and properties of related binary and trinary blends. The self-adhesiveness of the blends of PEDOT:PSS, WPU, and SOR is related to the plasticization of PSS^- (or PSSH) by SOR, the interaction of PSS^- (or PSSH) and SOR with the substrate, and the facilitation of the energy dissipation by the flexible WPU. Moreover, we demonstrated novel self-adhesive blends consisting of PEDOT:PSS, SOR, and PSSH that are used to substitute WPU. Although PSSH is not an elastomer, it can be plasticized by SOR and can thus facilitate the energy dispersion like WPU through the blends. These blends can have high mechanical stretchability and high self-adhesion to various substrates as well.