A confined-etching strategy for intrinsic anisotropic surface wetting patterning.

Anisotropic functional patterned surfaces have shown significant applications in microfluidics, biomedicine and optoelectronics. However, surface patterning relies heavily on high-end apparatuses and expensive moulds/masks and photoresists. Decomposition behaviors of polymers have been widely studied in material science, but as-created chemical and physical structural changes have been rarely considered as an opportunity for wettability manipulation. Here, a facile mask-free confined-etching strategy is reported for intrinsic wettable surface patterning. With printing technology, the surface wetting state is regulated, enabling the chemical etching of setting locations and efficient fabrication of complex patterns. Notably, the created anisotropic patterns can be used for realizing water-responsive information storage and encryption as well as fabricating flexible electrodes. Featuring advantages of simple operation and economic friendliness, this patterning approach brings a bright prospect in developing functional materials with versatile applications.