Think back to elementary school science — you probably learned that plants have vascular systems responsible for carrying nutrients and water to different parts of the plant. This system has lots of branches that sort of resemble circuits. If you could introduce an electrically-conductive material into the plants, you'd be on your way to creating actual organic electronics.
That's the goal of a research project that Swedish scientists have been conducting. They've used conductive polymers to form hydrogel within a rose's vascular system. One cool part about this experiment is that the rose does most of the work. The scientists had to snip a rose at the stem and place the stem in a solution containing the polymers. The rose's vascular system drew the material in and distributed it throughout the rest of the plant.
They used a different technique to introduce conductive wires into rose leaves. They placed a leaf into a syringe filled with cellulose and the conductive polymer. They used the syringe to create a vacuum, which pulled air out of the leaf. Nature — including roses — abhors a vacuum, and so when the scientists allowed the syringe to return to normal pressure the mixture of cellulose and the polymer entered the leaf through the stomata.
When the scientists applied an electric current to the leaf they could change the color of the leaf. It didn't exactly turn the leaf into a high-definition display. Instead, the charge created a light-dark pattern across the leaf. Reversing the voltage reversed the pattern.
But why would anyone want to turn plants into organic circuits in the first place? Is this just a case of mad botanical science? The researchers offer several potential uses for the technique. One is that it could allow biologists to monitor plant cycles on a much more precise level, increasing our knowledge on how plants actually work.
With that knowledge, we might be able to grow plants more effectively, which could increase harvest yields and lower food costs. And the researchers suggest a few more ideas that fall into the realm of science fiction — organic electrochemical fuel cells or using photosynthesis to generate electricity, for example.
So the next time you give or receive roses, remember it's not just a gesture of affection. You're handing over some pretty high-tech gadgetry!