Most people are probably familiar with the natural spectacle of bioluminescence from stays by the sea, for example in Moskito Bay on the Caribbean island of Puerto Rico. If you swim here in the dark, the water begins to glow mystically green-blue. Researchers led by Chenghai Li from the University of California San Diego are now proving that this mysterious natural spectacle could also be helpful in a scientific context. They developed a soft but durable material that begins to glow as a result of mechanical stress such as pressure, stretching or twisting.
The main components of the bioluminescent material are single-celled algae, so-called dinoflagellates, which ensure the glow. The material’s glow corresponds to what happens in the ocean when dinoflagellates produce flashes of light as a defense strategy against predators. The dinoflagellates are mixed with alginate, an algae-based polymer, after which they are processed using a 3D printer and finally cured. Ecoflex, a stretchy, rubber-like polymer is used as a coating to make the material robust against acidic and basic conditions. The picture of the week shows a variety of shapes such as spheres, blocks, grids, spirals and spider webs, which were formed using the 3D printer.
The sensitivity of the material is particularly impressive. Even with the gentlest touch or when drawing patterns on the surface, the material lights up. The rule applies here: the higher the load, the brighter the glow. The team emphasizes the simplicity of the material. It requires no electronics or external energy sources and only minimal maintenance requirements. As in nature, dinoflagellates require periodic cycles of light phases to produce food and energy through photosynthesis, and dark phases in which this energy is emitted as a flash of light upon mechanical stress.
Uses as mechanical sensors, in soft robotics or in biomedical devices as well as the use of light signals for treatment or the controlled release of medications are currently conceivable. And all thanks to the power of nature.