Structural elasticity for tensile deformation of a single human hair and the comparison with it for the bending deformation

Hironori Tohmyoh, Kento Fujita, Hitoshi Suzuki, Kei Futada

Research output: Contribution to journalArticlepeer-review

Abstract

Human hair is a multi-layered structure, which consists of the inner medulla, middle cortex, and outer cuticle. Therefore, the mechanical properties of the hair are related not only to the Young's modulus of each layer but also to the internal structures. Although the tensile test of a human hair has been performed elsewhere, the deformability of the hair for the tensile deformation is determined as the Young's modulus of the hair structure, which is similar to that of metals. In this paper, the structural elasticity of a single human hair for the tensile deformation, which expresses the deformability of a hair by tension without being dependent on external dimensions and shape, is defined based on the theoretical model, and is measured by performing the tensile test under the digital microscope observation. The values of the structural elasticity for the tensile deformation of the hair samples collected from healthy persons are compared with the values obtained for bending deformation. The structural elasticity for the tensile deformation of the hair sample is found to be lesser than that of the bending deformation, and this is verified to be always valid provided the Young's modulus of the outer cuticle is greater than that of the middle cortex.

Original languageEnglish
Article number104166
JournalJournal of the Mechanical Behavior of Biomedical Materials
Volume113
DOIs
Publication statusPublished - 2021 Jan

Keywords

  • Bending deformation
  • Cuticle
  • Human hair
  • Internal structure
  • Structural elasticity
  • Tensile deformation

ASJC Scopus subject areas

  • Biomaterials
  • Biomedical Engineering
  • Mechanics of Materials

Fingerprint Dive into the research topics of 'Structural elasticity for tensile deformation of a single human hair and the comparison with it for the bending deformation'. Together they form a unique fingerprint.

Cite this