In Situ Sintering Integrated With Jet Dispensing for Energy-Efficient Fabrication of Printed Stretchable Conductors

Scalable manufacturing of flexible electronics requires printing processes that facilitate the immediate functionalization of conductive traces without interrupting continuous production. This work introduces an energy-efficient hybrid manufacturing platform integrating jet dispensing with in situ near-infrared (NIR) sintering. This platform enables rapid post-deposition consolidation of silver flake inks within a continuous workflow. Stable jetting behavior is achieved through the optimization of dispensing parameters, and a multi-pass, three-phase gradient NIR strategy is developed to produce homogeneous, defect-free conductive traces. The printed conductors exhibit a low resistivity of 12.48 µΩ cm, which is comparable to oven-cured counterparts and among the lowest reported values for silver-flake inks, while maintaining electrical integrity under 20% tensile strain. Microstructural and chemical analyses indicate that gradient NIR exposure progressively fluidizes the polymer binder, forming a thin, continuous coating over the silver flakes, thereby contributing to enhanced mechanical robustness. The gradient NIR sintering process is completed in 16.4 s using 1644 J of energy. This represents a 73-fold reduction in processing time and a 620-fold reduction in energy consumption compared to conventional oven curing. The proposed jet dispensing–NIR platform offers a scalable and energy-efficient pathway for the continuous fabrication of high-performance stretchable electronic conductors.