The widespread use of RFID (radio-frequency identification) tags in retail and logistics has streamlined supply chains. However, it comes at an environmental cost. Over 10 billion RFID tags are produced annually, most of which are discarded after a single use. Engineers at the University of Glasgow have developed a potential alternative; a chip-free wireless sensor system that could significantly reduce the electronic waste associated with RFID technology.
Traditionally RFID tags need microchips to store and transmit data, but these new wireless tags work without requiring any semiconducting elements. The sensing system integrates conductive coils with a sensing material that consists of polydimethylsiloxane (PDMS) infused with carbon fibres. This technology utilises multiple components to capture electromagnetic reader signals which results in component identification alongside time-sensitive temperature readings without requiring complex electronics.
These tags become more economical and environmentally friendly through the removal of microchips; as then basic manufacturing methods become the go to way of manufacturing. The researchers see potential usage for their sensors in retail, food safety, healthcare, and even smart textiles applications due to the lightweight and flexible nature of the sensors.
The James Watt School of Engineering’s Dr. Benjamin King is a co-author of the paper. He said
“The new technology we’ve developed uses materials which are cheap and widely-available, and the tags can be manufactured using a simple, scalable process. Our hope is that those unique characteristics could help the technology become widely-adopted in the years to come, helping to reduce the environmental harms currently being caused by single-use RFID tags.”
Dr. Mahmoud Wagih, lecturer at the University of Glasgow’s James Watt School of Engineering, is the study’s corresponding author. He stated
“Developing wireless sensing tags is crucial for monitoring temperature across supply chains, particularly in food safety and medical applications. By eliminating the need for microchips, these chipless tags could significantly reduce both cost and electronic waste compared to traditional RFID sensors.
“While there have been various efforts in recent years to develop chipless smart devices, many require expensive specialised equipment for readout, limiting their potential in commercial applications.
“Our paper shows how multiple temperature sensors can be read simultaneously using an inexpensive portable device, which could make it an attractive prospect for adoption by a wide range of industries.”
In lab tests, the sensors demonstrated the ability to detect temperature variations between 20°C and 110°C, with optimal performance in the 20°C to 60°C range; critical for applications in food safety and medical supply chains. The tags also proved capable of being read simultaneously, with multiple sensors transmitting data to a single reader device. Additionally, the simplicity of the handheld reader, which costs under £100, could make this technology accessible for large-scale adoption.
The ability to integrate additional functionalities, such as pH or humidity monitoring, suggests a future where these tags could be embedded into packaging to provide real-time data on food spoilage. Similarly, their application in wearable technology could enable seamless health monitoring without the bulk and expense of conventional electronic components.
Wireless sensors without chips offer industries a valuable option to decrease e-waste generation while improving tracking efficiency across multiple business sectors. The development of this technology has the potential to modify supply chains and healthcare monitoring while introducing smart packaging solutions which present an eco-friendly substitute for current RFID-based systems.
