The concept of "green energy" got a whole lot more literal last week, when scientists announced they'd successfully turned living roses into electronic circuits. That's right — cyborg flowers are now a thing.
Despite how it sounds, the aim isn't to create a race of leafy green borg that will one day rise up and enslave their human masters. Instead, think smart plants that can sense and display environmental changes, or crops whose growth can be regulated at the flick of a switch.
Or plant-based fuel cells that convert the photosynthetic sugars into electricity. The very first electronic plant, developed by researchers at Linköping University in Sweden and described this week in Science Advances, is a step toward any one of those applications and many more.
"As far as we know, there are no previously published research results regarding electronics produced in plants," said study lead study author Magnus Berggren in a statement. "No one's done this before."
Here's how it's done: first, the the researchers introduce a synthetic polymer called PEDOT-S into the rose through its stem. The plant sucks up the polymer using the same vascular system (xylem) that transports water. Once inside xylem channels, the polymer self-assembles into an "wire" that conducts electrical signals, while still allowing water and nutrients to move around. By connecting these wires with naturally-occurring electrolytes in the plant's tissue, the researchers are able to create an electrochemical transistor, as well as a digital logic gate, a basic component of computer systems.
The researchers also introduced a variant of PEDOT-S into the leaves, where it forms "pixels"; groups of electrochemical cells separated by leaf veins. When a voltage is applied, these pixels change colour like a display.
The first cyborg plant is the culmination of two decades of work — the researchers first tried to hack electronics into trees in the '90s, but funding fell through — and yet it seems we've only scratched the surface of what's possible with this technology.
"Now we can really start talking about 'power plants' — we can place sensors in plants and use the energy formed in the chlorophyll, produce green antennas, or produce new materials," Berggren said. "Everything occurs naturally, and we use the plants' own very advanced, unique systems."
[Read the full scientific paper at Science Advances]
Top image: Chris Sorge / Flickr