Near-Field Soil Moisture Sensor with Energy Harvesting Capability

摘要

A battery-less NFC tag able to sense soil moisture, temperature and relative humidity is presented. The effect of the distance between the reader and the tag, as well as the effect of the presence of metal close to the antenna, has been studied to assure that the magnetic field generated by a commercial smartphone is stable enough to power up a microcontroller and the other components of the tag. The sensor has been experimentally validated.