Radio-frequency identification (RFID) sensors are one of the fundamental components of Internet of Things that aims at connecting every physical object to the cloud database for exchange of information and activities. Consequently, the development of low-cost, efficient, printable RFID sensors is a fundamental research domain for this future high-technology era. RFID is a powerful wireless technology for automatic identification and tracking, access control, security and surveillance and electronic toll payments. However, so far RFIDs have not fully replaced the widespread barcodes due to the higher tag price, which is determined mainly by the need of incorporation of a silicon chip.

Chipless RFIDs are a breakthrough technology because they remove the cost associated with the chip, overcoming the main economic limitation. Moreover, they are also printable, passive, low-power and suitable for harsh environments. A chipless sensor is basically made by one or more RF resonant structures, whose frequency is dependent on the dielectric material covering the metallic resonator. While the general structure of the sensor is common to all types of chipless sensors, the properties of the dielectric material are responsible for the sensitivity to specific parameters.

In this project, we exploit chipless RFID technology for ionising radiation sensing. We plan to fabricate a radiation sensor prototype where the sensing material is one or more suitable polymers, to test it under radiation and evaluate its application in wireless remote sensing environments.

For remote monitoring of ionising radiation the current technologies, based on solid-state detectors or scintillators, need complicate signal transmission methods, prone to environmental interferences. On the other hand, flexible reliable detectors for ionising radiation are still to come. Our approach meets these two requirements, realising a product which is at the same time extremely cheap and easy to fabricate and suitable for wireless remote sensing.

The immediate application is foreseen in the field of high-dose radiation detectors. This sector needs urgently a relatively simple, cheap and easy-to-use sensor of high radiation, in order to reliably measure high-dose levels inside new or existing nuclear reactors, or the post-process storage of nuclear wastes or contaminated sites. Low-cost wireless ubiquitous tagging and sensing will make the systems more efficient, reducing waste of money and resources, enabling a faster response to emergencies and lowering the probability of accidents.

In a second step, the material and design optimisation will allow us to lower the detection limit of the device, opening the way to a broader range of applications, going from environmental control to medical and healthcare applications.