Scientists Can Now Watch Materials Fail in Real Time
Professor Horacio Espinosa explains how that could speed the design of better batteries and chips
For decades, scientists have studied materials mostly by comparing what they looked like before and after being stressed, bent, heated, or damaged. Now, that is changing.
In a new review article, Northwestern Engineering’s Horacio Espinosa describes how advances in in situ nanoscale mechanical characterization are allowing researchers to watch materials deform, crack, and transform in real time. Instead of relying only on static snapshots, scientists can now directly observe the tiny mechanisms that determine whether a material will be strong, durable, brittle, resilient, or prone to failure.
The shift could help researchers design better materials for technologies people depend on every day, from longer-lasting batteries and more durable microelectronics to lightweight structural materials and advanced protective systems.
The review, “In Situ Nanomechanical Characterization of Functional and Architected Materials,” was published June 3 in Nature Materials was led by Espinosa, the Walter P. Murphy Professor of Mechanical Engineering at the McCormick School of Engineering.
“Materials do not fail all at once or for mysterious reasons,” Espinosa said. “Failure begins through small-scale mechanisms, such as defect formation, crack initiation, local strain buildup, or phase changes. We can now observe many of those processes as they unfold, and that is changing how we understand materials and how we design them.”
The review explains how the field has moved beyond conventional before-and-after testing. Today’s tools can probe materials while they are under realistic operating conditions, including mechanical loading, heat, and chemical or electrochemical environments. That makes it possible to see not only what failed, but how and why it failed.
This new capability is especially important for emerging materials whose performance depends on features at very small scales. These include atomically thin materials for electronics, architected materials designed for high strength and low weight, biomaterials, and materials for energy storage and conversion.
The review also highlights how several once-separate techniques are now being combined into a more powerful toolkit. Electron microscopy can reveal structural changes as they happen. X-ray methods can look inside materials and capture three-dimensional internal evolution. Opto-acoustic techniques can probe elastic and dynamic behavior without touching the sample. Together, these approaches give scientists a much richer picture of how processing, structure, and properties are connected.
“Different methods answer different parts of the same question,” Espinosa said. “When they are combined, we gain a much more complete understanding of material behavior under realistic conditions.”
The combination of advanced characterization, automation, and AI can accelerate the discovery and optimization of next-generation materials.
That matters because many of today’s engineering problems depend on understanding damage before it becomes catastrophic. Researchers want batteries that last longer, chips and devices that remain reliable as they shrink, and lightweight materials that can absorb energy and resist fracture. Directly observing how materials behave at small scales can help scientists identify weak points earlier and design around them.
The review also points to the future of the field: automation, high-throughput experimentation, and artificial intelligence. Modern in situ methods can generate enormous volumes of data, far more than researchers can analyze efficiently by hand. By combining advanced experiments with machine learning, scientists may be able to identify promising materials faster and move beyond slow trial-and-error development.
“In situ experiments are becoming not only more informative, but also more scalable,” Espinosa said. “The combination of advanced characterization, automation, and AI can accelerate the discovery and optimization of next-generation materials.”
Rather than simply testing whether a material works, researchers are increasingly able to see the physical mechanisms behind its performance. According to Espinosa, that represents a fundamental change in materials science, one that could shorten the path from discovery to real-world technology.
Acknowledgments: This work was supported in part by the Air Force Office of Scientific Research (AFOSR, grant FA9550-20-1-0258), the National Science Foundation (NSF, grant CMMI-1953806), and the Office of Naval Research (ONR, grant N00014-22-1-2133).