Spotlight November 2022: Photonics in nature and bioinspired designs

Science has always taken nature as a model and imitated it. If you look at the field of photonics, i.e. the use of optical technologies for information processing, transmission or storage, the colorful examples in the animal and plant world are perfect basic drawers for technical applications.

While colors in nature are used either for communication, mating, camouflage, or as a defense mechanism, science is trying to translate them into engineering applications.
In the review “Photonics in nature and bioinspired designs: sustainable approaches for a colorful world” published by Raquel Vaz, Manuela F. Frasco and M. Goreti F. Sales, the authors describe the variety of colors in nature and on which physical phenomena, for example, the color change of chameleons is based. They show how science is using the underlying mechanisms to develop novel materials and applications from photonic crystals, colored biomaterials or optical sensors.

The colors found in nature come from either physical processes such as reflection or diffraction or chemical processes such as bioluminescence. The review article focuses on physical processes in which a certain structure that interacts with light is decisive for the colors we perceive. For example, the color of butterflies’ wings is caused by the nanostructure of chitin. Some fruits of trees are blue because the structure of cellulose reflects only blue light.

Derived from nature, numerous materials are suitable as photonic biomaterials. In general, the color or a change in color indicates a change in the environment of the material and can therefore be used as an indicator that is easily perceived by humans. Applications of such “indicators” include pharmaceuticals, where the release of drugs from a capsule can be monitored by a color change.
In the field of sensor technology, a change in color can be used to indicate a change in temperature or pH value. So-called “smart” plastic materials are used for this purpose, among others. They are able to detect changes in pH and temperature simultaneously. Other plastic materials can detect heavy metals or pollutants or are able to indicate the presence of biological warfare agents.
Many photonic applications are currently under development. For example, wearable photonic devices may be applied in determining health data such as measuring heartbeat or respiration. Other future application areas include better treatment of cancer or faster self-healing for tissue damage.

The field of photonics shows promising approaches for new materials and applications that cannot be realized with common dyes. Thus, photonics is a field of research from which many new developments for the diagnosis of diseases, the encapsulation of drugs or for the monitoring of chemicals in the environment can be expected in the future.

Original publication:

Vaz, Raquel and Frasco, Manuela F. and Sales, M. Goreti F. (2020). Photonics in nature and bioinspired designs: sustainable approaches for a colourful world. Nanoscale Adv.,2, 5106-5129.

This article is part of the themed collections: US National Nanotechnology Day, 2022.