Controllable ultrafast laser hybrid fabrication of biomimetic omniphobic polyetheretherketone surfaces for sustainable food processing

Superhydrophobic surfaces have attracted considerable interest in the food processing industry because of their ability to mitigate food residue accumulation and the resulting microbial proliferation. In the present study, we report a lotus leaf-inspired strategy combining texture with low-surface-energy modification to synergistically enhance the superhydrophobicity and ultralow adhesion of polyetheretherketone (PEEK). The prepared biomimetic superhydrophobic surface with multi-scale hierarchical structures (comprised of micro-papillae with low-surface-energy porous carbon crowns and wax particles) was synthesized by a hybrid method combining ultrafast laser micromachining with beeswax spin-coating. The unique configuration of the dual-scale micro-papillae hierarchical structure originated from two competitive mechanisms under multi-pass laser scanning—laser ablation and graphitization. Hence, its formation is highly sensitive to laser parameters. By establishing the correlation between process parameters, surface morphology and resulting antiwetting properties, diverse repellent surfaces with tunable micro/nano-structures can be flexibly fabricated. By comparison, the micro-papillae hierarchical structure with porous carbon crown exhibited optimal antiwetting behaviors among all the laser-fabricated hydrophobic structures owing to its low-surface-energy biomimetic design philosophy. Beeswax treatment further enhances hydrophobicity by providing additional surface roughness and effectively repairs defective or damaged samples, thereby promoting sustainable food processing. The combination of proven mechanical durability and omniphobicity positions the prepared superhydrophobic PEEK as an ideal candidate for diverse applications in food production scenarios.