Reconfigurable Infrared (IR) Emissivity of VO₂ Patterns Fabricated via Maskless Laser Writing for Adaptive IR Applications

Dynamic control of infrared (IR) emissivity is critical for applications such as adaptive thermal camouflage, radiative cooling, and smart coatings. Vanadium dioxide (VO2), a phase transition material, exhibits a temperature-driven insulator-to-metal transition, enabling reversible and actively tunable emissivity switching. In this work, we employ a maskless, lithography-free laser writing technique to fabricate VO2 patterns on vanadium (V) thin films, achieving precise spatial control of the emissivity through two different approaches. Our results demonstrate a wide passive emissivity modulation range from ∼0.1 to 0.9 along with reversible active emissivity switching in different ranges (maximum switching ∼0.8 to 0.3) at the VO2 transition temperature. To highlight the potential of this approach, we fabricate two thermally responsive checkerboard structures, one of which dynamically appears, while another disappears in IR imaging beyond the phase transition temperature. This scalable and precious laser writing method offers a powerful platform for adaptive IR camouflage, IR tags, anticounterfeiting, reconfigurable thermal management, IR scene generation, and energy-efficient smart surfaces.