From Chip-Based to Chipless RFID Sensors: A Review

Radio frequency identification (RFID) sensors have received increasing attention in recent years due to their wireless battery-free operation, low profile, simplicity, low cost, and multimodality sensitivity. They have found their way to everyday applications, including smart packaging for food quality assurance, early noxious gas detection, smart bandages for chronic wound assessment, and structural health monitoring. This work aims to provide a review of chip-based and chipless RFID sensor technology and to depict a transition from the former to the later one. This is conducted by highlighting existing challenges for implementation of chipless RFIDs, possible solutions to overcome these problems, and recent development introduced in the literature. Then, it has been demonstrated how RFID sensors in conjunction with artificial intelligence and machine learning can be applied for enhancing RFID tag sensitivity and selectivity to a high degree of accuracy. The focus of this article is on chipless RFID sensors, and at the end, we present a direction for future research work.