Characterizing poroelasticity of biological tissues by spherical indentation: An improved theory for large relaxation

Ming Wang, Shaobao Liu, Zhimin Xu, Kai Qu, Moxiao Li, Xin Chen, Qing Xue, Guy M. Genin, Tian Jian Lu, Feng Xu

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

Flow of fluids within biological tissues often meets with resistance that causes a rate- and size-dependent material behavior known as poroelasticity. Characterizing poroelasticity can provide insight into a broad range of physiological functions, and is done qualitatively in the clinic by palpation. Indentation has been widely used for characterizing poroelasticity of soft materials, where quantitative interpretation of indentation requires a model of the underlying physics, and such existing models are well established for cases of small strain and modest force relaxation. We showed here that existing models are inadequate for large relaxation, where the force on the indenter at a prescribed depth at long-time scale drops to below half of the initially peak force (i.e., F(0)/F(∞) > 2). We developed an indentation theory for such cases of large relaxation, based on Biot theory and a generalized Hertz contact model. We demonstrated that our proposed theory is suitable for biological tissues (e.g., porcine liver, spleen, kidney, skin and human cirrhosis liver) with both small and large relaxations. The proposed method would be a powerful tool to characterize poroelastic properties of biological materials for various applications such as pathological study and disease diagnosis.

Original languageEnglish
Article number103920
JournalJournal of the Mechanics and Physics of Solids
Volume138
DOIs
StatePublished - May 2020

Keywords

  • Diffusion coefficient
  • Mechanical characterization
  • Porous biomaterials
  • Shear modulus, Poisson ratio

Fingerprint

Dive into the research topics of 'Characterizing poroelasticity of biological tissues by spherical indentation: An improved theory for large relaxation'. Together they form a unique fingerprint.

Cite this