Fluorescent Molecules to see when and where Molecules Break during Mechanical Fatigue

2026-07-22

Although elastomers are widely used in load-bearing engineering applications where lightweight and flexibility is essential, they are typically designed thicker than they need to be, due to a poor prediction of their lifetime in use. The loss of flexibility and extensibility results from individual covalent bond scission in the bulk of the material. When the extent of bond scission increases or localizes in specific spots, the rubber becomes brittle and can break catastrophically, potentially causing an accident. Detecting the early stage progressive molecular scale damage during use is impossible with current techniques using ultrasounds or X-rays. Within the framework of the ERC project CHEMECH we have precisely developed a method to detect, image and quantify bond breakage. This technique is based on tagging model materials with molecular probes (i.e., fluorophores) that become fluorescent when they break in response to a mechanical force. The goal of the current proposal is to incorporate the fluorophores in a variety of elastomers and to develop a novel methodology for non-destructive visualization and quantification of early damage by bond scission occurring in elastomers during cyclic mechanical testing. Compared to existing ultrasound and X-ray solutions, our technology detects degradation occurring at a much smaller scale (10 nm), can localize the damage more precisely and is non-destructive allowing the monitoring of the damage evolution in time. This information can then be used to refine the prediction of lifetime to design parts lighter and with less material, to schedule maintenance and part replacement more accurately, preventing catastrophic failures while saving time and money and finally to find new materials design strategies and expand the use of lightweight polymeric materials into new applications where they could replace metals or ceramics.

France

2026-02-15