What is RFID?
RFID tags, or Radio Frequency Identification tags, are really quite neat.
These small tags use radio waves to communicate with a "reader", a machine that
reads the tag from a distance. What makes them cool is their size and
cost. Why? Because new technologies have allowed scientists to build
these tags very small - small as a regular price tag on a shirt at the store.
Also, they are cheap to make now too - some only cost a few pennies to make.
This opens up the possibilities of what we can do with RFID technology.
For instance, RFID tags can be used in credit cards so we don't have to run them
through a reader. Since they use radio waves, you can simply keep the
credit card in your pocket and the reader can read it without you having to take
it out.out.
RFID tags can be used as price tags too. Rather than scan each item in
your shopping cart one by one, the entire cart can simply be pushed to the
register and the reader will read each item in the cart without you having to
take them out.
Also, RFID tags can hold a lot of information in them - much more than just
price. And unlike a paper price tag, they can be updated from a distance.
For instance, if a RFID tag is used as a price tag on a new shirt and the shirt
goes on sale, a store clerk does not have to put a new tag on the shirt.
The reader simply sends a radio signal to the RFID tag to update the price.
How does RFID work?
There are two types of RFID tags today - active (and semi-passive) and passive.
Active RFID tags have internal batteries which lets them transmit long distances
(100 feet or more). Passive RFID tags, the ones that are so cool, do not
use batteries and instead, draw power from the RFID reader machine. The
downside to passive RFID is that they cannot broadcast over as long a distance
as the active RFID tags can - passive RFID is limited to around 20 feet or so.

What does the future hold?
That's anybody's guess. Here's a scenario of how RFID tags could
work:
Let's look at a real-world scenario of this system:
- Let's say you go to the grocery store and buy a carton of milk. The milk
carton is embedded with a miniature RFID tag. When you take the carton
out of the store's refrigerator, a RFID reader reads the information on the tag
including the price and when it will expire. If it is expired, a light
flashes to let you know the milk is old.
- As you leave the store, you pass through doors with an embedded tag reader. This reader tabulates the cost of all the items in your shopping cart and sends the grocery bill to your bank, which deducts the amount from your account
automatically. In addition, the store's computers are updated letting them
know that one item of milk went out the door (and then could automatically
determine and order another carton if needed).
- When you get home, you put the milk in your refrigerator. Your refrigerator
is also build with a RFID reader that reads the milk when you walk in the door.
If after 20 minutes, the refrigerator does not detect that the milk was placed
in the refrigerator, it screams at you. The smart refrigerator is capable of tracking all of the groceries stored in it. It can track the foods you use, how often you restock your refrigerator and can let you know when that milk and other foods spoil.
Products are also tracked when they are thrown into a trash can or recycle bin. At this point, your refrigerator could add milk to your grocery list, or you could program the fridge to order these items automatically.
Did you know?
- Passports are now embedded with RFID tags so the government can track easier
- Companies are already making RFID "firewalls" that protect fraidy cat people
from RFID readers getting their personal information.
- RFID tags have been used on cattle for quite some time (even when the RFID
technology first came out and was very expensive). Now people are
beginning to embed their pets with RFID chips.
- Some RFID chips are so small, they can be embedded into a single piece of paper!