Israel Kellersztein

Congratulations to Israel Kellersztein, Zuckerman Faculty Scholar in Ben-Gurion University’s Department of Materials Engineering, on the upcoming publication of  Hydration and length scale define fracture energy in hierarchical biological composites in Engineering Fracture Mechanics.

The ability of structural materials to resist fracture is often more critical than strength alone. Whether in aerospace components, biomedical implants, or protective devices, materials must not only carry load but also tolerate flaws without catastrophic failure. This longstanding challenge has driven interest in systems that integrate both strength and toughness, often through diverse hierarchical toughening strategies. Dr. Kellersztein  examined hydration effects and energy on fracture resistance in biological composites and demonstrated how water content and length scale govern the amount of energy dissipated near a crack’s tip. This, in turn, determines fracture’s energy and resistance.

Abstract:
Hierarchical biological composites achieve exceptional damage tolerance through a combination of structural organization and environmentally activated dissipation mechanisms. Fracture toughness is widely used to quantify this performance, yet its physical meaning in biological materials is often obscured by their strong sensitivity to hydration and length scale. In these systems, water modifies molecular mobility, interfacial interactions, and microstructural deformation, thereby controlling which energy dissipation mechanisms are activated during crack advance. Here, we critically examine fracture mechanics studies across biological and engineered materials to show that hydration and length scale fundamentally govern the physical meaning of measured fracture resistance.