Scientists are developing rechargeable, glow in the dark plant life that could eventually replace many of our current, inefficient and energy-intensive electric lighting fixtures.
Technology works by embedding nanoparticles near the surface of leaves. The plant can glow brightly for several hours with a 10-second charge from an LED lamp. After that, the nanoparticles may be recharged repeatedly.
This research is part a growing field called plant bionics, which uses nanoparticles to give living plants additional functions and capabilities. This technology is now in its second generation.
Michael Strano, MIT chemical engineer, says, "We wanted to make a light-emitting plants with particles that absorb light, store some, and emit it slowly." This is a major step towards plant-based lighting.
(Strano et al., Science Advances, 2021)
Capacitors are the heart of glowing plants. They can store photons and then release them over time. Strontium aluminate, a compound that can absorb ultraviolet and visible light and emit it as a glow, was used to make the phosphor.
To protect the microparticles from damage, you can form Strontium Aluminate into nanoparticles. The microscopic dots were embedded in plant stomata, which are tiny pores on the leaves' surface that allow gases to flow in and out. They then accumulate as a thin layer within the mesophyll-tissue layer.
The technology was successfully applied to five plant species: basil, watercress and tobacco.
Pavlo Gordiichuk, MIT nanoscientist, says that "we need an intense light," which is delivered in a pulse for a few seconds and can charge it.
We also demonstrated that amplified light can be transmitted a greater distance than 1 meter using large lenses such as Fresnel lenses. This is a great step towards creating lighting that people can use.
Left: An illuminated Thailand elephant's ear. (Strano et al., Science Advances, 2021)
Further analysis showed that the plants could still photosynthesize normally and could continue to evaporate water via their stomata. The scientists were able extract and reuse approximately 60% of the phosphors used in the experiments.
The technology is even more promising because it is a major upgrade to the first-generation nanoparticles that were used to make glowing plants. These used the luciferase enzymes (found in fireflies) and produced a dim glow.
Researchers say that different types of nanoparticles can be mixed in the same plant.
Although this technology is not yet practical, the average leaf lifespan for charging seems to be around two weeks. It's a great innovation that we should keep an eye out for, and could change how we view the world.
Sheila Kennedy, MIT architecture researcher, says that creating ambient light using the renewable chemical energy from living plants is a bold idea.
It is a fundamental shift in the way we think about lighting and living plants.
Science Advances published the research.