Science

Glow-in-the-dark plants could act as passive lighting for public spaces

Glow-in-the-dark plants could ...
A microscope image of the glowing nanoparticles (highlighted in green) inside the plants
A microscope image of the glowing nanoparticles (highlighted in green) inside the plants
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A microscope image of the glowing nanoparticles (highlighted in green) inside the plants
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A microscope image of the glowing nanoparticles (highlighted in green) inside the plants
A diagram showing where the nanoparticles accumulate inside the plants
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A diagram showing where the nanoparticles accumulate inside the plants
A few examples of the glow
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A few examples of the glow-in-the-dark plants
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A decent chunk of energy usage goes towards lighting, so scientists at MIT are developing a new kind of passive lighting – glow-in-the-dark plants. In the latest experiment, the team has made them glow much brighter than the first generation plants, without harming their health.

The emerging field of “plant nanobionics” involves embedding nanoparticles into plants to give them new abilities. Past work by the MIT team has created plants that can send electrical signals when they need water, spinach that could be used to detect explosives, and watercress that glows in the dark.

As interesting as that last one was, the glow wasn’t particularly bright – about on par with those plastic glowing stars many of us stuck to our ceilings as kids. That’s a cool novelty but not much help for the ultimate use case of passive lighting.

Now, the researchers have boosted the brightness to more practical levels. The key was to switch the glowing components from luciferase and luciferin – which give fireflies their glow – to phosphor materials. These materials absorb and store visible and ultraviolet light, and slowly release it as phosphorescence.

“Creating ambient light with the renewable chemical energy of living plants is a bold idea,” says Sheila Kennedy, an author of the study. “It represents a fundamental shift in how we think about living plants and electrical energy for lighting.”

In this case, the team used nanoparticles made of strontium aluminate as the phosphor, and coated them in silica so they didn’t damage the plants. These are then infused through pores in the leaves, and eventually accumulate in a layer called the mesophyll.

A few examples of the glow
A few examples of the glow-in-the-dark plants

After being exposed to light from the Sun or LEDs, the plants will glow green. The team tested the technique on a range of plants, including watercress, tobacco, basil, daisies and elephant ear, and found that just 10 seconds of exposure to blue LEDs makes the plants glow for up to an hour. As might be expected, the light is at its brightest in the first few minutes, before dimming over the next hour.

The light was 10 times brighter than the previous version, and importantly, the nanoparticle implants didn’t harm the plants’ normal functions, such as photosynthesis and evaporating water through their leaves.

The end goal, the team says, is to try to develop glowing plants that could be used to passively light up streets or other public areas, reducing the energy consumption needed for street lights. The next steps towards that goal is to combine the new strontium aluminate nanoparticles with the earlier luciferase ones, to hopefully make the glow brighter and longer-lasting.

“If living plants could be the starting point of advanced technology, plants might replace our current unsustainable urban electrical lighting grid for the mutual benefit of all plant-dependent species — including people,” says Kennedy.

The research was published in the journal Science Advances.

Source: MIT

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6 comments
6 comments
Username
10 minute exposure will make them glow for an hour. I suspect that a 3 hour exposure would also make them glow for only an hour.
McDesign
Wonder how "night sky" regulations would apply to glowing plants as area lighting - the rules require that only a very small percentage of area lighting is allowed to trespass "up" above 85-90°.
MikeofLA
Cool, so in the future, all city parks will look like Pandora from Avatar.
HoppyHopkins
About time someone finally thought of this. I thought about it the first time I ever saw a bio-luminescent tomato plant, thinking how cool it would be if shade trees could be developed with multi-colored glowing leaves (flame trees) as ornamental back yard lighting and street lighting. I also thought that house plants or globes of algae would be useful in 3rd world countries for cheap lighting, take it out during the day to absorb the sun and back in at night for lighting. Glowing shrubs could also reduce night time prowlers and burglars.
RSnyder642
So let's replant all our parks with plants full of strontium aluminate? How's the research going as to the cross pollinations of those modified plants and the unchanged plants, and their place in the food chain? Will the insects begin to glow in the dark too? Or just die, like maybe the bees?
One Engineer
Why not just paint the nano particles on surfaces? Is it just esthetically more pleasing to have glowing plants? Or does the embedding into plant tissue actually matter somehow?

Phosphorescence does not drive energy from biological activity, as I understand it.