Direct Laser Writing of Highly Conductive Flexible Copper Electrodes Using Short Wavelength Lasers

In this work, we present a material design and fabrication process for the direct laser writing (DLW) of fine copper patterns on flexible substrates using a low-power ultraviolet (UV) laser. By formulating specialized copper-based precursor inks, we demonstrate the formation of highly conductive, densely interconnected copper nanoparticle networks with high electrical conductivities for flexible electronic applications. Unlike conventional thermal or sintering-based methods, our technique relies on a photochemical reaction mechanism induced by UV laser irradiation at powers below 750 mW, enabling localized patterning without thermal damage to underlying materials. The process highlights the potential for scalable fabrication of flexible electronic devices. This work lays a foundation for future development of copper-based functional nanostructures, offering a low-cost, energy-efficient alternative for next-generation wearable and flexible electronics.