Radio-Frequency Identification

 Pawan Sharma, Ashwin G.

 (MSCLIS 2009)

RFID or the Radio-Frequency Identification refers to small electronic devices consisting of a small chip and an antenna. The chip usually is capable of carrying 2,000 bytes of data or less. The RFID device serves the same function as a bar code or a magnetic strip on the back of a credit card or ATM card; it provides a unique identifier for that object. And, just as a bar code or magnetic strip must be scanned to get the information, the RFID device must be scanned to recover the identifying information.

RFID Better Than Barcodes

A major advantage of RFID devices is that the RFID device does not need to be positioned accurately relative to the scanner. RFID devices will work within a few feet up for high-frequency devices of the scanner. For example, you can just put all of your purchases in a bag, and position the bag on the scanner. It would be able to calculate all of the RFID devices and total your purchase immediately.

RFID technology has been alive for more than fifty years. It has only been recently that the ability to produce the RFID devices has fallen to the point where they can be used as a throwaway list or control device. Alien Technologies recently sold 500 million RFID tags to Gillette costing ten cents per tag. The basic reason for RFID to come into common use after so long is the lack of standards in the industry. Most companies invested in RFID technology only to use the tags to track items within their control, many of the advantages of RFID come when items are tracked from company to company or from country to country.

Problems with RFID

Some regular problems with RFID are reader collision and tag collision. Reader collision occurs when the signals from two or more readers are related. The tag is unable to respond to concurrent queries. Systems must be cautiously set up to evade this problem. Tag clash occurs when many tags are there in a small area; but since the read time is very fast, it is easier for vendors to develop systems that ensure that tags respond one at a time.

How do RFID work?

 A Radio-Frequency Identifications system has three parts:

The antenna sends radio-frequency signals in a comparatively short range. The RF radiation provides two basic things:

This is a key part of the technology; RFID tags do not work on batteries, and can be in use for very long periods of time maybe decades. The scanning antennas can be enduringly affixed to a surface. Handheld antennas can also be used. They can be changed in shape according to your need; for example, you could implant them into a door edge to receive data from persons or objects passing through. When an RFID tag passes through the area of the scanning antenna, it detects the signal from the antenna. That trigger the RFID chip, and it transmits the information on its microchip to be picked up by the scanning antenna.

The RFID tag may be of two types. Active RFID tags contain their own power source; the benefit of these tags is that the reader can be much farther away and still get the signal. Some of these devices are built to have up to a 15 year life span, but still they have limited life spans. Passive RFID tags, on the other hand, do not require batteries, and can be much smaller and have a practically unlimited life span.

RFID tags can be read in an extensive variety of circumstances, where barcodes or other optically read technologies are ineffective.

 

How RFID is used in a living body?

 

RFID devices that are intended to be rooted inside a living body either an animal or of a human being need special requirements. They have to be enclosed in a special kind of covering that will not annoy or react with the living tissues that they are inserted into. The covering must also be apparent to the scanning radio-frequency beam that activates the chip. Some RFID vendors have produced biocompatible glass for use in these applications. One possible problem with being placed within a living organism is that the tiny RFID device may move around under the skin. This can be avoided by using special resources that actually let the adjoining tissue grow up to the casing and bond with it.

Because the radio-frequency waves that set in motion the microchip containing the identification number are only functional within a few feet, the RFID chip is usually inserted very close to the surface of the skin.

The microchip  .

A sample of an RFID chip for implanting in the human body

The insertion of the device is usually done with a hyperdermic-type needle. This method of placing also dictates the shape and size of the device; implantable RFID devices are normally the size and width of a grain of rice. For dogs, the device is generally implanted between the shoulder blades.

RFID tags have been located inside cows; some debate of having all cows implanted with RFID devices has resulted from the recent scare with mad cow disease. Dog owners have used RFID tags to identify their pets rather than tattoos, one of the traditional methods.

 

What can RFID used for?

RFID tags come in a large variety of shapes and sizes; they may be sheathed in a variety of materials:

RFID policies have been used for years to classify dogs, for a means of permanent identification. Dog owners had long used tattoos, permanent ink markings, usually on the ears. However, these can weaken with age and it may be difficult to get the animal to sit still while you examine him for markings.

Numerous musical instruments are stolen every year. For instance, custom-built or vintage guitars are worth as much as $55,000 each. Snagg, a California company specializing in RFID microchips for instruments, has implanted tiny chips in 30,000 Fender guitars already. The record of RFID chip IDs is made available to law enforcement officials, dealers, repair shops for evidence.