This is the second of three articles where we have the pleasure of talking to Martyn and learning all about RFID. If you're interested in emerging technologies, this is a series you won't want to miss.

David: How much does an RFID tag cost?

Martyn: Simple RFID tags like those embedded into printed adhesive labels cost in the neighborhood of 10 to 20 cents. The capacity of the microchip, the size/type of antenna and the type of substrate all factor into the cost, though, so a glass RFID tag meant to be embedded into an animal, or a rugged plastic keychain are obviously more expensive.

When you look at active RFID tags, they start around $20 and can get into the $100 range, once again depending on the capabilities of the tag itself.

Finally, there are WiFi based tags commonly used for real-time location tracking that have a similar price point to active tags.

David: What reads the tags? How expensive are the readers?

Martyn: RFID tags are read by RFID interrogators, which are often referred to as readers. In a passive RFID system, these devices have one or more antennas connected to them that emit the signal that powers the RFID tags and then keep track of the responses from the tags. They gather this data and send it on to software to be processed.

You can buy intelligent RFID readers with antennas from a number of different vendors for around $1,500 to $2,000. There are some less expensive in the $1,000 range, and some more expensive in the $3,000 range as well.

Just like RFID tags, there are different types of readers. There are "ruggedized" mobile readers that cost about $4,000-$5,000 and forklift readers for a similar price.

David: If everything's radiating a signal, are there any possible health implications?

Martyn: In the United States, the FCC governs the frequencies used by RFID and certifies all equipment for use. As with the frequencies used by cell phones, for example, the offices of the FCC, other international bodies, and companies in the various industries have performed and continue to carry out research and trials around the effects of radio frequency usage, ensuring the continued safe use of RFID