A new constitutive model for hydration-dependent mechanical properties in biological soft tissues and hydrogels

Xin Gao, Weiyong Gu

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

It is challenging to noninvasively determine the mechanical properties of biological soft tissues in vivo. In this study, based on the biphasic theory and the transport models, a new constitutive model for hydration-dependent mechanical properties in hydrated soft materials was derived: HA=A(1-ϕf)n(ϕf)2-n/(2-ϕf)2, where HA(=λ+2μ) is the aggregate modulus, ϕf is the volume fraction of fluid (i.e., hydration), A and n (>2) are two parameters related to the transport properties of the biphasic materials. A linear model for hydration-dependent shear modulus in the literature was verified for hydrogels. The effects of tissue hydration on mechanical properties (aggregate modulus and Poisson[U+05F3]s ratio) were investigated. It was found that the value of Poisson[U+05F3]s ratio was very sensitive to the tissue hydration in soft materials with high water content. The predictions of the aggregate modulus and shear modulus for hydrogels by the model compared well with those from experimental results. This study is important for developing new techniques for noninvasively assessing the mechanical properties of biological soft tissues using quantitative MRI methods as well as for designing scaffolds with proper mechanical properties for tissue engineering applications.

Original languageEnglish (US)
Pages (from-to)3196-3200
Number of pages5
JournalJournal of Biomechanics
Volume47
Issue number12
DOIs
StatePublished - Sep 22 2014

Keywords

  • Agarose gel
  • Aggregate modulus
  • Cartilage
  • Poisson[U+05F3]s ratio
  • Shear modulus
  • Soft materials
  • Water content
  • Water diffusivity

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'A new constitutive model for hydration-dependent mechanical properties in biological soft tissues and hydrogels'. Together they form a unique fingerprint.

  • Cite this