Researchers at Sweden’s Linköping University and the Swedish University of Agricultural Sciences have developed a way to create electronic circuits inside living plants. Noting the similarities in function between the vascular circuitry of plants and the components of discrete and integrated electronic circuits, the team demonstrated how roses can produce both analog and digital electronic circuits, which show potential for future use in regulating the plants’ physiology. Their findings appear in the journal Science Advances.
After many failed attempts to introduce conductive polymers through rose stems, the team found success with PEDOT-S. When the water-soluble synthetic polymer was absorbed into rose cuttings, it hardened into a thin film along the xylem — the channel through which the plant takes in water and nutrients — creating a wire that conducts electricity using electrolytes from the plant without interrupting the flow of water and nutrients.
A) Forming PEDOT-S:H wires in the xylem. A cut rose is immersed in PEDOT-S:H aqueous solution, and PEDOT-S:H is taken up and self-organizes along the xylem forming conducting wires. The optical micrographs show the wires 1 and 30 mm above the bottom of the stem (bark and phloem were peeled off to reveal the xylem).
B) Scanning electron microscopy (SEM) image of the cross section of a freeze-dried rose stem showing the xylem (1 to 5) filled with PEDOT-S:H. The inset shows the corresponding optical micrograph, where the filled xylem has the distinctive dark blue color of PEDOT.
C) SEM images (with corresponding micrograph on the left) of the xylem of a freeze-dried stem, which shows a hydrogel-like PEDOT-S structure.
Source: Science Advances
Magnus Berggren, a professor of organic electronics at Linköping University and one of the study’s authors, told The New York Times
the technology could, in the future, be used to regulate plant physiology, such as controlling the rate at which flowers bloom or timing their blooms to coincide with appropriate weather conditions or water availability. The result could be the ability to produce more resilient plants without exposing them to chemicals or genetic modification.
Other possible applications include harvesting small amounts of electricity from trees or other plants. “Today, the most natural way to convert the chemical energy of a tree is to burn it,” Berggren told the paper, “But maybe we could actually gently tap out some of the energy without killing it.”
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