Investigating Water Contamination with LoRa-Enabled Surface Acoustic Wave Sensors

This article presents the development and experimental evaluation of a wireless network of Love SAW (Surface Acoustic Wave) sensors for water contamination measurement in the Amazon region. The network uses a LoRa-based protocol based on RFM98 at the 433 MHz frequency band (Low Power Device). The sensor nodes rely on the mobile acoustic wave platform laboratory developed previously by our team. The instrumentation setup uses a nanoVNA to measure the S-parameters of the Love wave sensor. A Raspberry Pi collects and processes the data to obtain the essential characteristics of the sensor using a method developed in previous works. The unoptimized prototype successfully monitored a lake water quality at a node-to-node range of 700 meters for 36 hours. This work opens up opportunities for new applications in remote sensing and IoT (Internet of Things) systems for biological and health surveys in the amazonian basin.