The high content of vegetation water causes multiple electromagnetic resonances, which makes it possible to turn plants into an omnidirectional antenna. The finding may contribute to the development of environmentally friendly multifunctional devices.
Although plants are supposed to restrict the performance of radio-frequency transceiver systems (which is why the Wi-Fi signal becomes weaker in forests), they can also act as efficient biogenic elements, according to a study by an international team of scientists from the Moscow Institute of Physics and Technology (MFTI, for its acronym in Russian) and Tel Aviv University.
The research, published in AIP Publishing, determined that plants can not only limit signals, but, due to their high concentration of water, also act as elements of a dielectric resonant antenna that reinforces the electromagnetic field of objects.
The study focused on investigating the capabilities of the cactus ‘Opuntia ficus-indica’ to serve as an efficient antenna device, which could be customized and contribute to various applications of WLAN and Wi-MAX wireless technologies covering an ultra-wide frequency band.
” At the beginning of the project we were faced with at least two tasks: to increase the harvest using the electrodynamic properties of plants and to use the studied electrodynamic characteristics to improve Wi-Fi connectivity in forest areas,” explained Dmitri Filonov, head of the laboratory at the Center for Photonics and MFTI Two-Dimensional Materials, in a note published this Tuesday by Za Nauku magazine.
“For this, it was necessary to understand what chains and links aligned the liquids in plant capillaries.A living system has different electrodynamic parameters. By studying them using microwave analysis, we monitor the dynamics of plant growth and can plan competent and timely care,” he added.
“Having studied the electromagnetic structure, we wanted to solve the inverse problem: to use the system not for the purpose of absorption, but for radiation purposes, and at that time an antenna emerged from a cactus. It has become a real test of all our hypotheses: we know how a plant is organized from the point of view of electrodynamics, how it can influence signals and how it can be used for radiation”, summarized the scientist.
The high water content within the vegetation causes multiple Mie resonances, which are reinforcing effects of the electromagnetic field ethics of objects.
The stems of the cactus studied by the researchers are almost 75-85% water, which made it possible to use the plant as a Natural broadband omnidirectional antenna that operates in several Wi-Fi communication bands from 900 MHz to 7.7 GHz.
The scientists mathematically described how the resonances of the stem are organized, they connected a source to it, and the cactus began to generate electromagnetic radiation. The scientists explain that they chose ‘Opuntia ficus-indica’ for the research for the simple reason that it is very common in Israel. Also, it is often found in arid and desert areas, where establishing a wireless connection is a difficult task.
Further research on plants as functional electromagnetic elements may aid the development of environmentally friendly multifunctional devices and other green technologies, the paper’s authors concluded. .