A Raman Spectroscopy Investigation of the Resilience of Hair Cuticular Scales Under Uniaxial Stress

March 2026 in “ Journal of the mechanical behavior of biomedical materials/Journal of mechanical behavior of biomedical materials ”

Amalia Maria Paschou, Dimitrios Christofilos, John Arvanitidis, M. Katsikini

Raman spectroscopy hair cuticles uniaxial stress disulfide crosslinks gauche-to-trans conformational shift sulfur-rich A-layer exocuticle hydrogen-bond strength α-helix β-sheet keratin-associated protein Cell Membrane Complex hair cuticle keratin hair structure hair resilience

Studysummary This study investigated the mechanical response of the human hair cuticle to strain and found that cuticular deformation directly corresponded with fiber elongation, revealing significant molecular-level changes in disulfide crosslinks but maintained structural stability, highlighting the role of the cuticle in stress resistance. Our plain-language summary of this paper — not a Tressless recommendation.

This study uses Raman spectroscopy to examine the resilience of human hair cuticular scales under uniaxial stress, focusing on their mechanical behavior. It finds that stretching hair increases the distance between cuticle scales and creates iridescent regions near scale edges, emphasizing the cuticle's role in hair's mechanical response. The research identifies three stress-strain behavior regions: elastic, plastic deformation, and failure. In the plastic region, scales follow macrostrain linearly, while in the failure region, keratinocyte coherence is lost. Disulfide bridges change geometrically, but keratin structure remains unchanged. The study underscores the cuticular cell membrane complex's importance in maintaining structural integrity through lipid layer thinning and scale gliding.

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