Reading your favorite book by the light of a plant could become a reality.
Imagine a world where streetlights, traffic lights and other signs are no longer produced by light bulbs, but by plants. This idea, as poetic as it is intriguing, has already been the subject of numerous studies. In 2017, MIT researchers distinguished themselves with a fascinating paper on the subject.
At the time, researchers started by extracting luciferase and luciferin. These are two well-known enzymes, since they are the source of the characteristic glow of fireflies. It then only remains to fix it on nanoparticles in order to integrate it into the plant via various bioengineering techniques.
A very interesting proof of concept, but with limited applications. Indeed, these plants produced very little light. A 10cm watercress plant, for example, only emitted a thousandth of the light needed to read comfortably. Since then, researchers have therefore worked to increase the intensity and duration of illumination.
A vegetable optical capacitor
They return today with a new improved and even more promising version, spotted by SlashGear. And this new generation displays considerable progress in this area. In their paper, the researchers explain that these new plants glow with a ten times higher intensity to the originals! To achieve this, they had an absolutely brilliant idea: to turn the whole plant into light condenser.
The advantage of a standard electric capacitor is that it can store an electric charge proportional to the voltage applied to it. Except that here, the researchers don’t care about the electric current; what interests them is light. Instead of storing electrons, they racked their brains to create an optical “capacitor” capable of storing photons.
They then had the idea of using strontium aluminate; it is a so-called phosphor material, which emits light when stimulated. Once packaged in the form of nanoparticles, the researchers integrated it into the inner part of the sheet to form their capacitor.
Elegant, clean and recyclable
Result: the film formed inside the plant is able to absorb and restore photons from the sun or even from a simple LED. It suffices to expose the plant for ten seconds, and it will emit light for an hour. And there is even better: the plant can be “recharged” continuously for two weeks. This technique even works on a whole bunch of plants. The researchers thus tested tobacco or basil. For the record, strontium aluminate is harmless; provided that the silica is not inhaled, it would therefore be theoretically possible to produce a bioluminescent pesto. To the best of my mind! More seriously, the researchers also tested the elephant’s ear. With its large surface, this plant could one day be used for urban lighting.
According to their tests, this technique did not no impact on vital functions of the plant. Once the experiment was over, the researchers even managed to extract and reuse 60% of the strontium aluminate. So this is an approach that could be quite viable in the long term.
But before hoping to replace the bulbs, researchers will still have to increase light intensity. For this, they will now try to combine their 2017 approach with this new concept. And if they succeed, we could literally see bloom a new generation of lamps auxiliary and urban lighting.
The research paper is available here.