Over the last decade we have witnessed significant rise in the no. of wirelessly networked devices and the technical advancements over last few years in the field of wireless and internet network technology have contributed to diffusion and pervasiveness of IoT sensing technologies and wireless standards.
Various everyday items such as lamps, smartphones, washing machines as well as animals and people can be a part of this ever present IoT network if they are provided with a unique ID (UID) and if they are capable of sharing and transmitting data over the internet. As it happens we now have more than 15B IoT devices connected over the internet, sharing data and communicating and this network of devices is only bound to increase, expanding to 30B devices by the year 2030, as per a report.
The internet of things, with technologies such as BLE, RFID, UWB, RTLS and various proximity sensors and telemetry sensors, has truly become the internet of everything but there is an urgent need of developing new low power consuming, miniaturized, and low cast devices. Radio Frequency Identification has been a part of Internet of Things since the inception and even today it has been the most contributing technology.
Though UHF RFID sensors find many applications in network devices such as item level tagging and remote data collections, development in the field of Chipless RFID is quite revolutionary. Chipped RFID tags have high costs and the cost becomes a deal breaker when large scale RFID implementation is required. Currently an UHF RFID tag costs around 4-5 cents and even though it is very less individually and the prices are coming down heavily (from 40-50 cents per tag to 4-5 cents per tag), chipless RFID presents with a much inexpensive alternative that can be used on a mass scale.
What is Chipless RFID? How it is different than chipped RFID tags?
In order to reduce the cost of deployment of RFID technology, the best method adopted so far is the development of chipless RFID, a method that involves eliminating the silicon IC (integrated circuit)/microchip. It can be equipped with sensing capabilities while keeping the cost extremely low. It can be customized and printed, and developed in masses, capable of being functional in harsh environments. When fabricated using biodegradable materials, it can also be a sustainable option that doesn’t harm the environment.
In theory, chipless RFID is a passive RFID tag that has an antenna but not a chip. Instead of a silicon microchip the technology uses linear encoders for storing the data. Two popular types of chipless RFID based on encoding technique are Time Domain and Frequency Domain.
The chipless RFID has been pitched as an efficient alternative to barcode for it combines the benefits of RFID with the low cost (less than a cent) associated with a chipless RFID as well as it outcomes the issues relating to functioning of chipped RFID in harsh environment. Since it doesn’t contain an IC, the information is encoded inside a the tag based on time (the encoded data is represented as the amount of delay between the backscattered signals), Frequency (where information is encoded in the frequency response of the tag) or image (data is represented by the specific shape or symbol of the tag) or a combination of all these methods (hybrid chipless RFID tags) for enhanced data capacity. This allows it function efficiently even in harsh environmental conditions such as frost, rain, heat etc.
Chipless RFID and IOT
For sensing purposes (say IoT applications), the quantity of the data/info stored in the tag is not a critical parameter as the data required here is much less than what is required for tracking assets. And perhaps this is one of the most significant reasons behind the soaring inclination towards chipless RFID for IoT sensing applications. Moreover, the identification of the tag and sensing can be made on the similar resonating structures on the same tag.
The chipless RFID market is witnessing a huge growth driven by high demands in businesses such as retail and supply chain that are looking to automate the business operations using cost-effective means such as Chipless RFID. The chipless RFID market is witnessing a great CAGR of 28.1% and estimated to reach 6,660.5m USD in 2030 from current 1176.7m USD in 2023.
To conclude, the chipless RFID is the new alternative to chipped RFID tags. Since the chipped RFID tag fabrication is itself a costly process and the presence of an IC chip renders it inefficient in harsh environments, Chipless RFID tags offer just the opposite. Apart from AIDC, chipless RFID are also very useful for sensing applications in IoT where cost is an important factor.