Radio Frequency Identification (RFID) is a technology that uses radio waves to transfer data from an electronic tag, called RFID tag or label, to a receiver within a range of a few metres. These RFID tags are small and can be attached to objects to identify and track them.
This technology has been around since 1970 but it was too expensive to be used on a large scale. These tags were expensive because they were inductively coupled RFID tags which had a complex system of metal coils, antennae and glass. Then came the capacitively coupled tags which could be mass manufactured at a significantly lower cost. They used conductive carbon ink instead of metal coil to transmit data. There has also been a considerable decrease in the size of RFID. There are RFID chips as small as 0.05 * 0.05 millimetres.
Every RFID tag works in the same way:
- Data is stored in an RFID microchip.
- When the tag’s antenna receives electromagnetic energy from an RFID reader’s antenna, the tag sends back radio waves to the reader.
- These waves are decoded by the reader and data transfer is complete.
There are three types of RFID tags:
- Active tags: There RFID tags use internal batteries as a power source. They hjave a range of around 30 m which can be boosted to 100 m by using additional betteries.
- Semi-passive tags: They too have batteries but are only activated in the presence or a reader.
- Passive tags: Passive RFID tags rely entirely on the reader for power. They use the electromagnetic energy of the radio waves emitted by the reader. They are small in size and cheaper to manufacture. Because of the limited power source, they have a short range of 6 m.
RFID technology was originally meant to replace bar codes. This could potentially save thousands of men hours spent waiting in lines for check out. With RIFD tags, you could just walk out of the store and the reader would automatically bill you for the products you have shopped.
It’s currently being used to track livestock. This is done by fitting animals with locations – tracking RFID chips. Pets are also being implanted with tiny RFID tags containing information about their owners and their medical history. More recently these RFID tags are implanted in humans. These tags contain all the medical history of the person and prove extremely useful for Alzheimer’s patients. However all hospitals are not equipped with RFID readers rendering the tag useless.
Though RFID is commonly used, it will take considerable technological advancement for it to become an everyday used technology.