Actin-based motility is a complex process in which the actin-polymerization is the primary force-generating motor machinery. It can produce protrusive forces through actin filaments polymerization and cross-link during lamellipodia protrusion in migrating cells and it is responsible for the intracellular motion of certain pathogens in infected host cells. We propose a multi-physics model for actin-based motility, stemming from continuity equations that account for the actin chemical kinetics. Thermodynamic restrictions are identified, moving from the multiplicative decomposition of the deformation gradient into chemical and elastic parts. Constitutive theory and chemical kinetics are prescribed to finally write governing equations for the multi-physics problem. The field equations are solved numerically with the finite element method. As a proof of concept, a one-dimensional model for actin-based motility of bacteria pathogens is studied.

基于肌动蛋白的运动是一个复杂的过程，其中肌动蛋白聚合是主要的产生力的电机机械。它可以在迁移细胞的板状伪足突出过程中通过肌动蛋白丝聚合和交联产生突出力，并负责感染宿主细胞中某些病原体的细胞内运动。我们提出了一个基于肌动蛋白的运动的多物理场模型，源于考虑肌动蛋白化学动力学的连续性方程。确定了热力学限制，从变形梯度的乘法分解到化学和弹性部分。本构理论和化学动力学被规定为最终写出多物理场问题的控制方程。场方程用有限元法数值求解。