Tissue growth model and its numerical simulation

Proposed a viscoelastic growth model and simulate it using FEM and PINNs

Most soft biological tissues feature distinct mechanical properties of viscoelasticity, which play a significant role in their growth, development, and morphogenesis (Figure 1a). To reveal the biophysical mechanisms, we first proposed a mechanobiological viscoelastic model in the framework of thermodynamics (Lin et al., 2025). Then, we used a more novel method, the physics-informed neural network (PINN) to simulate the tissue growth and morphological evolution (Lin et al., 2026), (Figure 2, and the open-source code in Github). With PINN, buckling occurs naturally under the critical states during the oscillated training process without introducing artificial perturbations. Our studies have demonstrated that viscoelasticity facilitates sustained tissue growth and significantly influences the critical conditions of surface wrinkling and tissue morphology. In the future, we hope to apply the cross-scale theories, e.g., the strain gradient viscoelasticity (Lin & Wei, 2020), to characterize the multiscale / crossscale properties of biological tissues.

Figure 1: The mechanobiological mechanisms of tissue growth and morphological evolution.
Figure 2: Diagram of PINNs for the implementation of viscoelasticity.

References

2026

  1. CMAME
    A Physics-Informed Neural Network Framework for Simulating Creep Buckling in Growing Viscoelastic Biological Tissues
    Zhongya Lin, Jinshuai Bai, Shuang Li, and 3 more authors
    Computer Methods in Applied Mechanics and Engineering, 2026

2025

  1. JMPS
    Mechanobiological modeling of viscoelasticity in soft tissue growth and morphogenesis
    Zhongya Lin, Weizhi Huang, Shuang Li, and 4 more authors
    Journal of the Mechanics and Physics of Solids, 2025

2020

  1. IJSS
    A strain gradient linear viscoelasticity theory
    Zhongya Lin and Yueguang Wei
    International Journal of Solids and Structures, 2020