Programmable microfluidics for dynamic multiband camouflage.

Achieving multiband camouflage covering both visible and infrared regions is challenging due to the broad bandwidth and differentiated regulation demand in diverse regions. In this work, we propose a programmable microfluidic strategy that uses dye molecules in layered fluids to manipulate visible light- and infrared-semitransparent solvent to manipulate infrared light. With three primary fluid inputs, we achieve 64 chromaticity values and 8 emissivities from 0.42 to 0.90. In view of the wide tuning range, we demonstrate that the microfluidic film can dynamically change its surface reflectance to blend into varying backgrounds in both visible and infrared images. Moreover, we fabricate the microfluidic device in a textile form and demonstrate its ability to match exactly with the colors of natural leaves of different seasons in the full hyperspectrum range. Considering the broadband modulation and ease of operation, the programmable microfluidic strategy provides a feasible approach for smart optical surfaces in long-span optical spectra.