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Updated: Jun 21, 2026

Synthesis of Keratin-based Nanofiber for Biomedical Engineering
Published on: February 7, 2016
Microstructure, elastic properties and deformation mechanisms of horn keratin
Luca Tombolato1, Ekaterina E Novitskaya, Po-Yu Chen
1Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093-0411, USA.
Abstract:
The structure and mechanical properties of the horns from a desert bighorn sheep, Ovis canadensis, were examined. Horns must be strong and durable as they are subjected to extreme loading impacts, making them superior structural materials. Horns are composed of alpha-keratin, a fibrous, structural protein found in hair, nails, claws and hooves. Horns have a lamellar structure (2-5microm in thickness) stacked in the radial direction with tubules (approximately 40x100microm in diameter) dispersed between the lamellae, extending along the length of the horn in the growth direction. Compression and bending tests were conducted in both rehydrated and ambient dried conditions. The yield strength and elastic modulus are anisotropic and are correlated with the orientation of the tubules. Rehydrated samples showed significant loss of strength and modulus. Microscopy of fractured samples revealed several toughening mechanisms: delamination and ligament bridging in bending and delamination and microbuckling of the lamellae in compression.
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