PPDA hybrid: a flexible and biocompatible platform for supercapacitor and strain sensing applications

Abstract

Flexible, biocompatible, and high-performance energy storage platforms that can intimately interface with biological systems are highly desirable for emerging on-skin sensing and wearable electronic devices. In this work, we report the development of a novel poly(pyrrole/dodecylthiophene/acrylamide) (PPDA) hybrid conductive material with a distinctive hierarchical porous structure. The PPDA hybrid integrates a self-assembled polypyrrole (PPy) and polydodecylthiophene/γ-CD (PDDT/γ-CD) nanotubular aerogel network within a biocompatible polyacrylamide (PAAm) hydrogel matrix. This unique nanoarchitecture, achieved through a templated method utilizing LCA-(DDT/γ-CD) nanotube solution as templates to form PPy/PDDT/γ-CD nanotubular network structures, endows the PPDA hybrid with exceptional properties. These include flexibility, biocompatibility, and enhanced electrical conductivity up to 1.6 S m⁻¹, outperforming conventional PPy aerogels. As a supercapacitor electrode material, the PPDA hybrid exhibits good electrochemical performance, with a specific capacitance of 149.6 F g⁻¹ at 1 A g⁻¹ current density and retaining 82.3% of its capacitance after 1000 cycles at 5 A g⁻¹. The hierarchical porous structure, combining the advantages of nanotubes and hydrogels, facilitates multidimensional electron transport, rapid electrolyte diffusion, and robust mechanical properties. Consequently, the PPDA hybrid maintains stable electrochemical performance even under various mechanical deformations, including folding at angles up to 135° and stretching up to 50% strain. In vitro biocompatibility studies further confirm the PPDA hybrid's suitability for biological interfaces. The multifunctional PPDA hybrid combines flexibility, high electrical conductivity, good electrochemical properties, and biocompatibility, making it a promising platform for a range of applications, particularly in flexible supercapacitor and strain sensing applications.