An integrated development hardware design for an advanced wireless Ag/AgCl sensor to acquiring biosignals form ornamental plants

摘要

Electrical signals (biosignals) in higher plants could be the information carriers in intracellular and intercellular communication during environmental changes and pathogens attack. Biosignals are currently acquiring by Ag/AgCl electrode attached on plants' shoots and leaves. These plants are usually placed in Faraday's cage (FC) to eliminate the signal-noise. In this paper, we present an integrated hardware design for the development of an advanced wireless Ag/AgCl sensor for plants' biosignals measurements. In order to avoid white Gaussian noise, 50 Hz power line noise as well as the noise of the operating electrical devices, microcontroller embedded systems and IEEE 802.15.4 communication protocol was used for the system performance. The electrical potential was measured on leaves of Chrysanthemum (Chrysanthemum moriflorum) plants using Ag/AgCl electrodes and recorded in data logger: i) placed inside the FC, ii) in a distance of 15 meter away from FC, connected by interface circuit via wire and iii) in a distance of 60 meter away from FC using a wireless embedded system for data transfer. The wireless connection between embedded systems of Ag/AgCl electrodes did not show signals errors. The wire transmission of biosignal showed harmonics-distortions in spectral analysis and the amplitude of biosignal showed modification at 50%. The same result was showed under the effect of a low power RF signal (1- 3,3 Mhz), which transmitted near the location of FC.