Research engineers from the Massachusets Institute of Technology have found a way to give RFID tags the capability to sense chemicals in their surroundings.
Making RFID tags that work as sensors could lead to the development of low-cost, reliable devices that effectively detect chemicals in the environment. To date, retailers and manufacturers are the primary users of RFID or radio-frequency identification tags.
RFID tags are produced in the form of paper-based labels equipped with antennas and memory chips. When placed in retail products like milk cartons, these tags work like smart signatures that transmit the product information to a radio-frequency reader. RFIDs are also used in keeping track of casino chips, animals, marathon runners, and even visitors to amusement parks.
To date, RFID tags are available in different configurations like battery-assisted and the passive varieties. However, both make use of small antennas which communicate with the radio-frequency reader.
Battery-assisted tags use batteries to power their chips while passive tags use the energy they harvest from the readers to sustain themselves.
Unfortunately, both tags that use antennas are prone to getting false positives or negatives which often make them unreliable. As a solution, the researchers turned RFID tags into sensors.
The team came up with a UHF or ultra-high frequency tag sensor configuration that is said to be less prone to interference and can also detect glucose in the environment. Sensing glucose allows the chip to produce an electric charge which powers the RFID tag.
The researchers are still working on improving their technology, hoping to create an RFID tag someday that could detect carbon monoxide.
“People are looking toward more applications like sensing to get more value out of the existing RFID infrastructure,” Sai Nithin Reddy Kantareddy, a graduate student from the MIT’s Department of Mechanical Engineering, said in a statement.
“Imagine creating thousands of these inexpensive RFID tag sensors which you can just slap onto the walls of an infrastructure or the surrounding objects to detect common gases like carbon monoxide or ammonia, without needing an additional battery. You could deploy these cheaply, over a huge network.”