Bioinspired programmable multi-scale surface architectures for toughening ceramic-polymer composites

Abstract

Natural materials like nacre achieve exceptional toughness through hierarchical designs that integrate structural and interfacial mechanisms. Inspired by these functional principles, we present a digitally programmable laser micromachining strategy to fabricate multi-scale surface architectures on ceramic-polymer composites. By integrating full-depth hexagonal macro-patterns with shallow diagonal micro-patterns into alumina-Surlyn® laminates, we engineer surface features that simultaneously enable crack deflection, bridging, and enhanced interfacial bonding. The combined patterned configuration absorbs nearly twice the energy of unpatterned ceramics under 20 J low-velocity impacts and exhibits superior resilience under repeated 2 J impacts. Post-impact zinc-iodide X-ray radiography and rebound-based performance metrics revealed reduced delamination and partial elastic recovery in patterned samples, confirming the role of multi-scale architectures in governing damage tolerance. To probe interface mechanics, double lap joint experiments measured average interfacial shear strengths of ∼11 MPa for Plain samples and ∼18 MPa for micro-patterned samples. Cohesive-zone finite element analysis reproduced crack evolution and confirmed higher mode II strain energy release rates for micro-patterned interfaces. Together, these mechanics-based insights show how hierarchical surface patterning tailors failure pathways across both the ceramic phase and the ceramic-polymer interface. Unlike conventional macrostructural mimicry, our experimental-numerical framework offers a scalable route to toughening brittle systems and designing impact-resistant materials.