Controllable Laser Printing of Aluminum Microceramics for Designable Structural Colors

Direct structural color printing enables the fabrication of customized patterns in a cost-effective manner without the need for complex procedures or costly equipment. However, it is still challenging to simultaneously achieve highly precise and stable structural color patterns while avoiding substrate damage and remaining both economical and environmentally sustainable. Here, a laser micro/nanoprinting strategy based on metal hydroxides is developed. An aluminum hydroxide ink is formulated to replace polymers or noble metal nanoparticles used in conventional color printing. Controllable growth of aluminum hydroxide with vivid structural colors is realized. The mechanism of laser-induced hydroxide growth and the correlation between processing parameters and structural colors are investigated. Customized color patterns and their applicability to information encryption and decryption are demonstrated. This strategy maintains the high precision of laser printing while avoiding substrate damage and costly or polluting inks, presenting great potential in designable structural colors.