Modeling Tunable Fracture in Hydrogel Shell Structures for Biomedical Applications

Abstract

Hydrogels are nowadays widely used in various biomedical applications, and show great potential for the making of devices such as biosensors, drug- delivery vectors, carriers, or matrices for cell cultures in tissue engineering, etc. In these applications, due to the irregular complex surface of the human body or its organs/structures, the devices are often designed with a small thickness, and are required to be flexible when attached to biological surfaces. The devices will deform as driven by human motion and under external loading. In terms of mechanical modeling, most of these devices can be abstracted as shells. In this paper, we propose a mixed graph-finite element method (FEM) phase field approach to model the fracture of curved shells composed of hydrogels, for biomedical applications. We present herein examples for the fracture of a wearable biosensor, a membrane-coated drug, and a matrix for a cell culture, each made of a hydrogel. Used in combination with experimental material testing, our method opens a new pathway to the efficient modeling of fracture in biomedical devices with surfaces of arbitrary curvature, helping in the design of devices with tunable fracture properties.

Advancements in Phase-Field Modeling for Fracture in Nonlinear Elastic Solids under Finite Deformations

“…They conducted creep tests driven by diffusion to investigate the slow mass transport phenomena in water gels, specifically crack initiation and evolution induced by drying. Zhang et al [75] proposed a graph finite element phase-field hybrid model to simulate the fracture behavior of a water gel-based curved shell, abstracting the water gel in the biomedical field as a shell and effectively improving the computational efficiency. Zheng et al [76] proposed a diffusion fracture-based rate-independent variational principle phase-field method, which can effectively simulate the fracture process of super elastic materials and water gels under different boundary conditions, and verified the robustness of the method.…”

A Boundary-Element Analysis of Crack Problems in Multilayered Elastic Media: A Review

“…The phase field method (PFM) has become a popular numerical method for the analysis of the crack problems in recent years, since its implementation is free of crack tracking algorithms, enabling relatively easy simulation of complicated crack patterns, such as nucleation, branching, and coalescence [25][26][27][28]. The PFM, however, requires highly fine discretization due to the small length scale and becomes staggeringly computationalresource intensive as a result [29][30][31], severely limiting its application in actual industry.…”