Implementation of high-performance, freestanding flexible film masks through photosensitive polyimide for arbitrary surface micropatterns creation

Given the widespread presence of intricate surfaces, the development of electronics has generated a significant demand for surface patterning techniques capable of creating refined or novel patterns. Nevertheless, present surface patterning techniques suffer from complex processes, limited resolution, stringent conditions, and high manufacturing costs. Herein, we present a novel approach for arbitrary surface micropatterning using photosensitive polyimide (PSPI), enabling the in situ fabrication of electrodes without the need for a pattern-transferring process. On this basis, we have implemented a high-performance, freestanding flexible thin-film mask with high optical transparency that facilitates precise alignment of microelectrode patterns with the target material. It also exhibits exceptional mechanical properties suitable for long-term use and high-temperature applications, with a notable glass transition temperature of up to 300°C. The fabricated masks with thicknesses of 5–20 μm are well-suited for high-resolution applications, including those requiring sub-5 μm resolution. Furthermore, the creation of microelectrodes on a variety of surfaces utilizing the fabricated PSPI masks was successfully demonstrated. Our facile method provides a solid foundation for achieving efficient micropatterning for the fabrication of high-performance flexible electronics on complex surfaces.