Scientists headed by a team from the University of Massachusetts Amherst recently reported a major theoretical and experimental breakthrough that enables researchers to foretell when a soft material will crack and fail with unprecedented precision.
UMass Amherst professor of polymer science and engineering Alfred Crosby. Image Credit: University of Massachusetts Amherst.
The observations of the research have immediate implications for the engineering and production of various polymers. They also shed light on how natural soft materials, like the connective tissues and brains in the human body, break down. The study was published in the Proceedings of the National Academy of Sciences.
Predicting when a soft material, like a gel or an elastomer, will crack and fail is extremely difficult.
It’s been a mystery. But if we could predict exactly when a product would fail, and under what conditions, we could engineer materials in the most efficient way to meet those conditions.
Alfred Crosby, Study Senior Author and Professor, Polymer Science and Engineering, University of Massachusetts Amherst
As scientists could not predict when a soft material will fail, designers often over-engineer their products and advise replacing them sooner rather than later to be safe.
Alfred Crosby, Gregory Tew, also a professor of polymer science at UMass Amherst, and Robert Riggleman, professor of chemical and biomolecular engineering at the University of Pennsylvania, collaborated on this research, which was funded by the Office of Naval Research’s Naval Force Health Protection program.
The researchers employed a combination of highly precise chemistry, detailed and innovative computer modeling, and fine-grained experimental data, and modified an older theory, known as the Lake-Thomas Theory, with the help of a newer molecular model known as Real Elastic Network Theory (RENT).
As a result, using only the molecular ingredients, we can now accurately predict when a soft material will fail at both the molecular and product levels.
Ipek Sacligil, Study Co-Lead Author and Graduate Student, Polymer Science, University of Massachusetts Amherst
“This project highlights the importance of addressing modern scientific problems from multiple perspectives. By combining our efforts, we were able to craft a comprehensive story that is far greater than the sum of its parts,” adds Christopher Barney, one of the study’s other co-led authors and a graduate student at UMass at the time he completed this research.
This advance provides a missing link between chemistry and materials science and engineering for polymer networks.
Alfred Crosby, Study Senior Author and Professor, Polymer Science and Engineering, University of Massachusetts Amherst
Crosby also mentions that this research is part of a larger, ongoing project to comprehend more about the mechanics of cavitation, or sudden, unstable crack-causing expansions in soft materials and tissues.
Journal Reference:
Barney, C. W., et al. (2022) Fracture of model end-linked networks. Proceedings of the National Academy of Sciences. doi.org/10.1073/pnas.2112389119.