Design optimization of many biodegradable medical implants is hampered by a lack of appropriate modeling tools. In these applications, the implant?s geometry and the mechanical loads to which it is subjected may be quite complex. This leads to spatially varying strain fields within the implant, which can cause certain parts to degrade faster than others. Unfortunately, the ability to model spatially dependent strain accelerated degradation is not well developed, and completely absent in the finite element modeling (FEM) tools commonly used in the medical device industry. FEM involves using computational techniques to solve for stresses in structures with complex geometries.
The Moore laboratory has begun constructing material description models for strain accelerated biodegradation processes. While initially successful in describing general characteristics, the further application of these models requires extensive model refinement. This GOALI proposal between Texas A&M University and ANSYS, Inc. aims to provide these next steps in model development. Specifically, the objectives are: 1. Evolve the initial biodegradable material models through an extensive set of measurements of the biodegradation behavior of several polymers subjected to physiologic cyclic loading. 2. Ensure the applicability of these models by deploying them in the ANSYS Mechanical Analysis FEM software package. The availability of such modeling techniques will be of great benefit to medical implant designers who desire a predictable time to structural breakdown. There is significant value brought to the project by the participation of the industry partner, ANSYS, Inc. Their modeling software is being used by a large number of medical device manufacturers, all of whom are trying to develop biodegradable implants.
The development of these models will benefit communities other than medical device designers. Still within the biomedical community, there are many efforts to design functional tissue engineered constructs that can replace diseased body parts. In many cases, these constructs are made from biodegradable materials that are replaced by the actions of embedded or surrounding cells. The modeling techniques developed in this project will be applicable to these situations, with the addition of parameters that represent cell actions. Outside the biomedical community, there are many situations in which other sorts of materials experience strain accelerated degradation, including the built environment (man-made structures), automotive, and aerospace sectors. The commercial availability of these new models will benefit all of these fields, and educate a broader audience on the potential wide-ranging benefits of these new material models. The participation of the industry partner, ANSYS, Inc. adds significant value in making these models available to a broad community and publicizing their potential benefits. The post-doctoral and undergraduate researcher training aspects will benefit groups that are under-represented in engineering (females).