Bio-inspired design of fibre interfaces with intermittent weak and strong areas for obtaining tough composites

One of the most ambitious goals in structural materials is to achieve exceptional mechanical properties, with an ideal combination of light weight, high strength, and high toughness. For many biomaterials, strategies to achieve the advantageous unification between structure and mechanical properties have been through millions of years of evolution, as in the case of nacre, one good example of a material that combines high strength, high stiffness, and high toughness.Inspired by nature strategies to increase toughness, BioInter proposes to engineer the interface of composites by creating alternate sections around the fibre and along the fibre length of high and low adhesion with the matrix using micro-plasma surface deposition and activation, promoting intermittent sections of high and low shear strength during the process of debonding. The strong regions ensure that the filament strength is taken, while the weak areas weaken the running crack, creating a complex pattern for crack evolution.