Research on developing plant roots capable of conducting electricity

A new research project from Linkoping University (Sweden) has proven that using plant roots as an energy storage device is a viable option.

This method requires the plant to be watered with a special solution.  As a result, their roots are able to conduct electricity. The scientists see this process as a proof of concept for root-based supercapacitors, as well as systems that combine biological processes with electronics.

The conductive root system was developed by Linkoping University (Sweden).

Made at the university's Organic Electronics Laboratory, the breakthrough builds on previous research by the Electronics Factories Group, led by Dr. Eleni Stavrinidou. The study was published in the journal Materials Horizons.

In 2015, these scientists successfully engineered electrical circuits in the vascular tissue of roses by quantifying the plant with a conductive polymer called PEDOT .

The electrical circuit is then used to form a semiconductor. In 2017, the scientists added a conjugated oligomer called ETE-S instead. From there, form polymers in plants with the ability to turn into electrical conductors that can store energy.

'We've worked on cuttings before. This plant can accept and organize conductive polymers or oligomers. However, cuttings can only live for a few days and stop growing.

In this new study, we used original plants, namely a common bean plant grown from seed. We found that the plants were able to conduct electricity when they were irrigated with a solution containing the oligomers,' Dr Stavrinidou said.

The pea plant used in the group's experiments is known as Phaseolus vulgaris . The team added polymerization of the ETE-S conjugated oligomer found in the irrigation solution as part of a natural process.

Thanks to this solution, a conductive polymeric film appears on the roots. The solution then turns the entire root system of the plant into a network of electrical conductors. This electrical conductivity can last for more than four weeks.

Scientists have adapted to use this plant as a supercapacitor. The stumps then act as the system's electrodes during charging and discharging. Scientists have discovered that tree stumps can store up to 100 times more energy than previous systems that used only the trunk. This new method does not appear to have much effect on the survival of the plants. Thus, allowing the system to be used for a long time.

'The tree developed a more complex root system, but nothing was affected. It continues to grow and produce beans," said Dr. Stavrinidou.

According to the researchers, this work opens up a promising avenue for integrating energy systems into living plants without affecting their biological functions. Prior to that, there were many research projects focused on biosimilar integrated systems. Some aim to turn plants into organic monitoring sensors.

Meanwhile, other projects involve creating 'machine plants' capable of orienting themselves towards light. The development of conductive plant roots by scientists at Linkoping University could be a useful addition to this area of ​​research.