BEER-SHEVA, ISRAEL, June 9, 2026 — Scientists at Ben-Gurion University of the Negev (BGU) have uncovered for the first time the "ingenious" biological strategies that allow blue-tailed damselflies to produce strikingly vivid, angle-independent colors. The study, published in the Proceedings of the National Academy of Sciences (PNAS)(https://www.pnas.org/doi/10.1073/pnas.2527433123), provides a new blueprint for creating sustainable, highly saturated photonic materials that could replace toxic synthetic pigments in industries ranging from cosmetics to textiles.
Structural colors in nature are often produced by photonic glasses—randomly arranged nanospheres that scatter light. While efficient, these systems typically suffer from poor color saturation because slight variations in particle size (polydispersity) wash out the resulting hue.
The damselfly's secret: structural dispersion
The research team, led by Prof. Benjamin A. Palmer and PhD student Tali Lemcoff from BGU's Department of Chemistry, discovered that blue-tailed damselflies (Ischnura elegans) overcome these physical limitations using two elegant evolutionary solutions:
- Self-Correcting Particles: To keep the color sharp, damselflies ensure that as spheres get larger, their density (refractive index) drops. This "structural dispersion" means that regardless of their size, every sphere reflects the exact same shade of blue or green.
- Built-in Color Filters: The damselflies "load" their spheres with a yellow pigment. This pigment acts like a filter, absorbing messy, unwanted light while making the main color appear much deeper and more saturated.
"Nature has found an elegant way to produce perfect colors using imperfect parts," says Lemcoff. "These strategies could show us in the future how to build high-quality optical materials using sustainable, organic ingredients instead of the synthetic chemicals we rely on today".
Lemcoff is a recipient of an Azrieli Graduate Fellowship.
The interdisciplinary team included researchers from the Weizmann Institute of Science, Lund University, Aalto University, and the University of Bristol.
This work was supported by the European Research Council (Grant No. 852948, "CRYSTALEYES" and Grant No. 101096020, "BoX-BOOM"), the Human Frontier Science Program (Grant No. RGP0037/2022), the Israel Science Foundation (Grant Nos. 1565/22 and 833/23), and the Research Council of Finland (Grant No. 347789).
