A Self-Cleaning Hierarchical Thermal Cloak

Abstract Thermal invisibility is a topic that has captivated the research interest for decades. Recent theories envisioned the promising schemes for this purpose using the near-wavelength antennas; because it enabled precise control over the radiation for invisibly cooling while preserving the cloaking within detectable band. However, pushing this delicate device to real-world applications raises two essential challenges: large-scale fabrication of the structures featuring nanoscale accuracy and durably safeguarding the function from both erosion and various contaminant intakes. Here, we reported a hierarchical self-cleaning thermal cloak using the scalable femtosecond laser writing to overcome such limitations. The cloak was engineered with finely configured dynamic superhydrophobic microcolumn arrays; on top of the microcolumns, the antennas was devised for direct tailoring with the ultrafast laser writing to ensure the large-area manufacturing scalability and feasibility. We demonstrate that the co-created architecture has superior cloaking performance with mechanical and thermodynamic durability; moreover, it enables self-sweeping of the contaminants through Van Der Waals forces of an impact bulk droplet, thus completely regaining the excellent thermal cloaking. This harmonized design and manufacture may unlock the access of thermal cloak to more expanded opportunities in future.