A new generation of glowing plants

MIT engineers used special nanoparticles embedded in plant leaves to create a light-emitting plant that can be charged by LEDs
.
After charging for 10 seconds, the plants will glow for a few minutes, and they can be charged repeatedly

The light produced by these plants is 10 times brighter than the first-generation light-emitting plants reported by the research team in 2017
.

Michael Strano, Professor of Chemical Engineering Carbon P.
Dubbs at MIT and the senior author of the new study, said: "We want to create a luminous plant whose particles absorb light and store part of it.
Light, and then gradually released
.
" "This is a big step towards plant lighting

"Using the renewable chemical energy of living plants to create ambient light is a bold idea," said Sheila Kennedy, a professor of architecture at the Massachusetts Institute of Technology (MIT)

These particles can also promote the luminescence of any other type of light-emitting plant, including those originally developed by the Strano laboratory

Former MIT postdoc Pavlo Gordiichuk is the lead author of this new paper published in the journal Science Advances
.

Optical capacitor

Strano's laboratory has been committed to a new field of plant nano-biomimetic for many years, which aims to give plants new characteristics by implanting different types of nanoparticles into plants
.
Their first generation of light-emitting plants contains nanoparticles carrying luciferase and luciferin, which work together to make fireflies glow

In this new study, Strano and his colleagues wanted to create components that can extend the duration of light and make it brighter
.
They thought of the idea of ​​using capacitors.

In order to create their "photocapacitor", the researchers decided to use a material called phosphor
.
These materials can absorb visible or ultraviolet light, and then slowly release it in the form of phosphorescence

These particles up to a few hundred nanometers in diameter can enter the plant body through stomata (small stomata located on the surface of the leaf)
.
These particles gather in a spongy layer called the mesophyll, where they form a thin film

This film can absorb photons from sunlight or LEDs
.
The researchers said that after 10 seconds of irradiating the blue LED, their plants can emit light for about an hour
.
In the first five minutes, the light was at its brightest, and then gradually weakened
.
As the team showed at an experimental exhibition at the Smithsonian Institute of Design in 2019, these plants can be charged continuously for at least two weeks
.

Gordiichuk said: "We need an intense light to be delivered in the form of pulses for a few seconds so that it can be charged
.
" "We also proved that we can use a large lens, such as a Fresnel lens, to magnify the light.
Transmission over a distance of one meter
.
This is a good step towards creating a scale of lighting that people can use
.
"

"The Smithsonian Institution's Plant Attributes exhibition showcases the vision of the future.
The lighting infrastructure of living plants is an integral part of people's work and living spaces," Kennedy said
.
"If living plants can become the starting point for advanced technology, then plants may replace our current unsustainable urban power grids, bringing common benefits to all plant-dependent species, including humans
.
"

Large-scale lighting

Researchers at the Massachusetts Institute of Technology found that the "photocapacitor" method can work in many different plant species, including basil, watercress, and tobacco, the researchers found
.
They also showed that they can illuminate the leaves of a plant called the Thai elephant ear, which may be more than a foot wide-a size that allows the plant to be used as an outdoor light source
.

The researchers also investigated whether the nanoparticles interfere with normal plant functions
.
They found that in 10 days, these plants were able to photosynthesize normally and evaporate water through the stomata
.
After the experiment, the researchers were able to extract about 60% of the phosphor from the plant and reuse it in another plant
.

Researchers in the Strano laboratory are now working on combining phosphor capacitor particles with the luciferase nanoparticles used in their 2017 study.
They hope that the combination of these two technologies can produce Plants that produce brighter light for a longer period of time
.