Researchers at Linkoping University in Sweden have created analog and digital electronics circuits inside living plants.
The group at the Laboratory of Organic Electronics (LOE), under the leadership of Professor Magnus Berggren, have used the vascular system of living roses to build key components of electronic circuits.
Plants are complex organisms that rely on the transport of ionic signals and hormones to perform necessary functions. However, plants operate on a much slower time scale making interacting with and studying plants difficult.
Augmenting plants with electronic functionality would make it possible to combine electric signals with the plant’s own chemical processes.
Controlling and interfacing with chemical pathways in plants could pave the way to photosynthesis-based fuel cells, sensors and growth regulators, and devices that modulate the internal functions of plants.
Researchers tried many attempts of introducing conductive polymers through rose stems. Only one polymer, called PEDOT-S, successfully assembled itself inside the xylem channels as conducting wires, while still allowing the transport of water and nutrients.
Scientist used the material to create long (10 cm) wires in the xylem channels of the rose. By combining the wires with the electrolyte that surrounds these channels she was able to create an electrochemical transistor, a transistor that converts ionic signals to electronic output.
Using the xylem transistors she also demonstrated digital logic gate function.
Scientists used methods common in plant biology — vacuum infiltration — to infuse another PEDOT variant into the leaves. The infused polymer formed “pixels” of electrochemical cells partitioned by the veins.
