Conformal Transfer Printing of PEDOT: PSS Patterns onto Structurally Complex Surfaces.

Fabricating conductive circuits on complex curved surfaces remains a significant challenge for conformal electronics, particularly for soft and additively manufactured polymer substrates. We report a robust, conformal GOPS-assisted transfer-printing strategy for integrating inkjet-printed PEDOT:PSS patterns onto traditionally hard-to-print and non-planar surfaces. In this approach, conductive features are first defined on a planar polyimide donor substrate and subsequently transferred to the target substrate. The incorporation of (3-glycidyloxypropyl)trimethoxysilane (GOPS) into PEDOT:PSS facilitates strong covalent bonding, ensuring exceptional interfacial adhesion and structural integrity of transferred patterns. This transfer process is compatible with diverse non-planar substrates, including compliant PDMS, curved glass, and stereolithography (SLA)-printed resins. While direct printing on these substrates often suffers from poor wetting or non-planar surfaces, this transfer strategy yields continuous pathways that preserve the original morphology and electrical performance. Transferred films exhibited excellent stability, maintaining functionality through repetitive bending and aqueous immersion without delamination. As a demonstration, a functional organic electrochemical transistor (OECT) was fabricated on a curved 3D-printed substrate through a multi-step process, independently transferring electrodes and a semiconducting channel, and exhibited concentration-dependent responses to dopamine from 5 to 1000 nM. These results establish a versatile route for integrating printed conductive patterns and functional devices on complex polymer geometries.