The development of low-cost, efficient, printable RFID sensors is a fundamental research domain for the Internet of Things (IoT). Chipless RFIDs are a new and emerging technology that removes the silicon chip from the sensor tag, including both the identification and the sensing function in the tag design. A chipless sensor is made by one or more RF resonant structures, whose frequency is dependent on the dielectric material covering the metallic resonator. This PhD position is about the study of chipless RFID technology for the sensing of environmental parameters. The study is interdisciplinary and will have different combined approaches: -At material level: study and identify the best polymer formulation for maximising the sensitivity to of parameters. At device level: build a sensor prototype with the most promising materials, for multi-parameter detection. Evaluate its performances with RF measurements, establishing also the suitability for wireless detection. The work will be primarily in FBK in collaboration with DII-UniTN.