Paper Number
BL10                         My Program 

Session
Biomaterials, Bio-fluid Dynamics and Biorheology

Title
Single cells are compactly and accurately described as Fractional Kelvin-Voigt Materials

Presentation Date and Time
October 20, 2025 (Monday) 2:30

Track / Room
Track 6 / Sweeney Ballroom C

Authors (Click on name to view author profile)

  1. Das, Mohua (Massachusetts Institute of Technology)
  2. Waeterloos, Jarno L. (KU Leuven, Department of Chemical Engineering)
  3. Clasen, Christian (KU Leuven, Department of Chemical Engineering)
  4. McKinley, Gareth H. (Massachusetts Institute of Technology, Mechanical Engineering)

Author and Affiliation Lines (in printed abstract book)
Mohua Das1, Jarno L. Waeterloos2, Christian Clasen2 and Gareth H. McKinley1
1Massachusetts Institute of Technology, CAMBRIDGE, MA 02139; 2Department of Chemical Engineering, KU Leuven, Leuven, Flanders 3001, Belgium

Speaker / Presenter 
McKinley, Gareth H.

Keywords
experimental methods; biorheology; gels; techniques

Text of Abstract
The mechanobiology of single cells plays a crucial role in various biological processes, including embryonic development, cancer treatment, and wound healing. We show that the rheological response of single cells can be well described by the fractional Kelvin-Voigt model (FKVM) - a linear constitutive model consisting of two Scott Blair mechanical elements arranged in parallel. Unlike traditional power law models, which primarily fit the key features of the mechanical response at long timescales, the FKVM captures both short- and long-timescale mechanical responses with a minimal number of constitutive parameters. We use the Bayesian Information Criterion (BIC) to demonstrate the parsimony of the FKVM description and its credibility compared to other proposed models. As a complete (linear) constitutive formulation the FKV model also enables prediction of the rheological response of cells in other modes of deformation. Experimental small-amplitude oscillatory shear (SAOS) data for dividing canine kidney cells, creep data of human K562 erythroleukemic cells, and creep-recovery data of blastomere cytoplasm are all analyzed to showcase the accuracy and versatility of the FKVM. Additionally, for the first time, the continuous relaxation and retardation spectra corresponding to the fractional differential formulation of the FKVM are derived, and a number of special limiting cases are considered. The results establish a comprehensive framework for predictive analysis of single-cell rheology in both the time and frequency domains.