Construction and conversion of 2D and 3D patterns on the surface of transparent polyethylene terephthalate induced by near-infrared laser

The patterning of transparent PET film plays an indispensable role in the application of packaging materials. However, traditional processes such as ink printing limit the pattern to a 2D plane. Recently, laser irradiation technology has been demonstrated as a potential strategy for achieving surface patterning of polymer materials. Here, we found that metallic oxide substrate can absorb laser energy and transfer it to transparent PET film through the interface, thereby improving the absorption of laser by PET. The preparation process of metallic oxide substrate is low-cost, scalable, and easy to prepare. Irradiation experiments were conducted at different energy densities, and the results show that the laser-induced patterns on the surface of PET film can be arbitrarily transformed between 2D and 3D. The PET film absorbs a large amount of heat through the interface with the substrate, which is the main factor regulating the pattern morphology. In addition, the controllability of photothermal conversion between interfaces enables laser-induced patterns to be designed locally and arbitrarily, thus achieving practical applications. The present method may open a new avenue for the application of laser patterning and meet the extensive requirements of transparent polymer materials in the fields related to surface 2D/3D pattern design.