Chapter two - The basic concept of viscoelasticity

Abstract

Viscoelasticity of multicellular system represents a product of energy storage and dissipation during cell rearrangement under various stress or strain conditions and should be considered in the context of cellular ability to relax obtained at various time scales. Various scenarios of relaxation are described by various constitutive models and can be considered in the time domain and frequency domain. Time domain corresponds to stress and strain change versus time while the frequency domain corresponds to interrelation between storage and loss moduli versus angular velocity. The basic concept of viscoelasticity in the context of linear models for (1) viscoelastic liquids such as the Maxwell model and the Jeffreys model and (2) viscoelastic solids such as the Kelvin–Voigt model, The Zener model, and The Four-parameter model, and (3) the model for describing jamming state were discussed. General characteristics of viscoelastic solids and viscoelastic liquids were extracted from this analysis and considered on various in vitro experimental systems.