Femtosecond laser-chemical hybrid processing for achieving substrate-independent superhydrophobic surfaces

Superhydrophobic surfaces have attracted considerable interest due to their various functions and wide applications. Most of the existing methods for preparing superhydrophobic surfaces are only applicable to one or several specific substrate materials, which have the disadvantage of substrate-dependent. Here, an approach for the fabrication of substrate-independent superhydrophobic surfaces based on femtosecond laser-chemical hybrid processing is proposed. Micro/nanostructures are constructed on substrates via femtosecond laser direct writing technology, followed by modification with stearic acid. The laser-treated samples coated with stearic acid (LTx-SA, x presents different samples) surfaces have excellent superhydrophobic and self-cleaning properties. Moreover, it is worth noting that the LTx-SA surfaces remain stable superhydrophobicity after heating substrate from 20 °C to 100 °C, washing substrate 10 times, and exposing substrate to air for 60 days. This work provides an efficient and facile strategy for achieving substrate-independent superhydrophobic surfaces.