Enhancing Accuracy and Interfacial Adhesion in PEEK-Based Conformal Electronics Fabricated via Hybrid Additive Manufacturing.

The hybrid additive manufacturing technology integrating fused deposition modeling (FDM) with laser-activated metallization (LAM) presents significant applications in the fabrication of three-dimensional conformal electronics. However, it usually faces challenges of poor pattern accuracy and low heterogeneous interfacial bonding strength. Aiming at the above issues in the integrated fabrication of polyetheretherketone (PEEK)-based conformal electronics, this study systematically investigated the underlying mechanisms and proposed dual optimization strategies. First, the decomposition characteristics of different precursors under ultraviolet picosecond laser irradiation were studied comparatively. Pd(OAc)2 decomposed more efficiently to generate more reactive PdO species on the PEEK surface than PdCl2, enhancing the efficiency of electroless copper deposition significantly. On this basis, an improved LAM method integrating directional gas flow-assisted laser activation and cleaning solvent optimization was proposed to reduce residual active substances in nonactivated regions, enabling the deposition of high-precision copper lines with 50 μm widths and 60 μm spacings. Furthermore, an N,N-dimethylacetamide (DMAc) cleaning and KH550 silane coupling agent grafting-assisted LAM method was proposed to enhance the PEEK-Cu interfacial adhesion strength. Micro/nano composite structures and chemically active groups were introduced on the PEEK surface, establishing a dual-reinforcement PEEK-Cu interface that combines mechanical interlocking and chemical bonding, resulting in a dramatic increase in interfacial adhesion strength from 3.3 to 29.4 MPa. Ultimately, the integrated fabrication of complex PEEK-based conformal electronics was achieved, with the verification of circuit accuracy and antenna performance. This work has provided both theoretical and technical insights into the integrated fabrication of high-performance conformal electronics, significantly advancing its broader applications.