Single-Step Fabrication of Poly(3, 4-ethylenedioxythiophene) Integrating Synthesis and Film Formation with Ease

Conductive polymers (CPs) are promising due to their intrinsic stretchability as the requirements for soft electronics increase. However, ongoing miniaturization to achieve high performance characteristics increases manufacturing complexity, limiting their applications. To address this challenge, we focused on a single-step fabrication platform that integrates synthesis and film formation of CPs on insulating substrates. We developed a novel single-step fabrication technique for soft electronics, termed the ADC-bipolar electropolymerization (EP) method. This technique was inspired by bipolar electrochemistry, where bipolar electrodes serve as active sites initiating polymerization without direct connection to external circuits. Our ADC-bipolar EP framework enables CPs film patterning at designated sites directly on insulating substrates, eliminating the need for photolithography and condensing synthesis and film formation into a single step. Building on the merits of ADC-bipolar EP, we easily fabricated poly(3,4-ethylenedioxythiophene) (PEDOT) films with high crystallinity and electrical conductivity. The structural and chemical compositions of PEDOT films were analyzed using grazing incidence wide-angle X-ray scattering, Raman spectroscopy, and X-ray photoelectron spectroscopy. The PEDOT films were successfully evaluated for their potential in electronics by demonstrating their use as organic electrochemical transistors and thermoelectrics. These results indicate the PEDOT films are suitable for use as active materials and electrodes. This demonstrates that our single-step fabrication platform effectively reduces manufacturing complexity and advances the development of cost-effective and disposable next-generation soft electronics.