The university announced the result on Thursday.
The compound belongs to a niche class called mechanochromic materials, which change color under mechanical influence such as bending or compression.
In normal conditions it appears yellow-green and, when stressed, turns red. The shift is reversible after adding an organic solvent that restores the molecular arrangement.
The researchers say the warning signal is most visible in the material’s luminescence under ultraviolet light, where the emission flips from yellow-green to red. In practice, a UV source or daylight with sufficient UV content would make the change easy to see.
“Think of every molecule as a tiny lock with matching keys,” said Konrad Szaciłowski, a professor at the AGH University of Kraków. “A gentle push rearranges them, the interactions flip, and the glow moves from yellow-green to red, a simple, visible warning.”
He added that a milligram of the relatively inexpensive compound is enough for a single-use sensor that can be replaced quickly.
The team says the material could be mixed into paints or polymers to create visual stress sensors on infrastructure and prototypes, without wiring or electronics.
Engineers would watch for localized color shifts that mark rising strain and intervene before damage accumulates.
“This system can be much more sensitive, and much cheaper to use, than advanced electronic sensors,” Szaciłowski said.
AGH says the project combined synthesis in Japan, advanced spectroscopy in India, and molecular modeling in Poland to explain why the color shift is strong and repeatable.
The researchers add that the compound’s responsiveness to organic vapors points to warning coatings for laboratories or factory floors, where a rapid color change would alert workers to exposure.
(rt/gs)
Source: polskieradio.pl