An RFID-enabled inkjet-printed soil moisture sensor on paper for “smart” agricultural applications

摘要

In this paper, an RFID-enabled inkjet-printed passive soil moisture sensor on paper for agricultural applications is presented and the design procedure, the operation principle and benchmarking experimental results are discussed in detail. A prototype made of a passive RFID tag integrated with a capacitive sensor, which consists of a printed interdigitated capacitor (IDC), has been printed on a low-cost paper substrate. The capacitance variation of the IDC shifts the resonant frequency of the RFID tag taking advantage of the soil-moisture based load matching variations since a matching condition changes due to the capacitive sensor. The proposed sensor can be easily integrated with conventional RFID systems for practical large-scale agricultural applications.