Variation in Young's modulus along the length of a rat vibrissa

Brian W. Quist, Rafay A. Faruqi, Mitra J Z Hartmann*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


Rats use specialized tactile hairs on their snout, called vibrissae (whiskers), to explore their surroundings. Vibrissae have no sensors along their length, but instead transmit mechanical information to receptors embedded in the follicle at the vibrissa base. The transmission of mechanical information along the vibrissa, and thus the tactile information ultimately received by the nervous system, depends critically on the mechanical properties of the vibrissa. In particular, transmission depends on the bending stiffness of the vibrissa, defined as the product of the area moment of inertia and Young's modulus. To date, Young's modulus of the rat vibrissa has not been measured in a uniaxial tensile test. We performed tensile tests on 22 vibrissae cut into two halves: a tip-segment and a base-segment. The average Young's modulus across all segments was 3.34±1.48. GPa. The average modulus of a tip-segment was 3.96±1.60. GPa, and the average modulus of a base-segment was 2.90±1.25. GPa. Thus, on average, tip-segments had a higher Young's modulus than base-segments. High-resolution images of vibrissae were taken to seek structural correlates of this trend. The fraction of the cross-sectional area occupied by the vibrissa cuticle was found to increase along the vibrissa length, and may be responsible for the increase in Young's modulus near the tip.

Original languageEnglish (US)
Pages (from-to)2775-2781
Number of pages7
JournalJournal of Biomechanics
Issue number16
StatePublished - Nov 10 2011


  • Elastic modulus
  • Elasticity
  • Strain
  • Stress

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine
  • Biomedical Engineering
  • Rehabilitation


Dive into the research topics of 'Variation in Young's modulus along the length of a rat vibrissa'. Together they form a unique fingerprint.

Cite this