3 comments by 1 or more people

1. Mathew Mannion

   RFID is already extensively used, for example in University library cards to scan people in and out of the library – how would this battery be any help? With a reader on either side of exits to the library, it could easily scan an RFID tag in a book inside someone's bag – it's just a case of linking that up with the user's library card in their pocket at the same time.

   20 Dec 2005, 15:01

2. Jenny Delasalle

   There are certain benefits that RFID has the potential to provide to libraries and their users. However, the technology is not quite there yet…

   Middlesex University have been a test site for RFID and they have reported problems with students being accidentally issued the books the person behind them in the queue wants to borrow at the same time as their own selection!

   Other problems are that the tags don't work well near metal, which includes metal shelving (which many libraries use, including us), and CDs and DVDs, which do form part of our collection: books which have accompanying CDs could be a problem, in this respect. RFID tags can be removed easily and are therefore not suitable for security. Also, the tags do clash from time to time, especially on thin books, so are no good for our pamphlet collections.

   The other obstacle for Warwick is obviously the scale of any operation to insert the tags into the entirety of the collection, and this would perhaps be more worthwhile once there are further standards for RFID tagging. At present, we could introduce the tags at great expense of time and effort, and then be tied into one supplier for all our issuing equipment, etc forever because the tags are not fully interoperable with other suppliers' RFID systems. Apparently standards are emerging, so this is one to watch.

   Read all about it in Library and Information Update, December 2005, p8: "Major benefits but technical glitches may spoil the RFID 'fun'.

   22 Dec 2005, 14:01

3. Dr Dean

   Some science for you non-antenna geeks out there:

   All radio-frequency (RF) energy ‘bounces off’ metal, just like throwing a tennis ball against a wall. As long as your RFID reader has a line of sight to the RFID tag, and is sufficiently close to pick up the signal (energy), the RFID system will work fine. However, put a shelf in the way and the energy will be reflected away from the reader. For such a low-energy system as RFID, the probability of receiving a reflection off another object is then going to be low. Interestingly, your mobile phone has to rely on such reflections in the cities, but the power levels are much higher and there are a lot of flat concrete reflecting surfaces to move the signal around, and windows to let energy in.

   For the small types of antenna used for RFID, the energy will be transmitted in a donut-like shape around the antenna; the direction and orientation of the tag’s antenna with respect to the reader will therefore also affect how much energy is received. If you fit a tag to a book on the shelf, you really want maximum energy to come off the shelf and not go down the shelf.

   Hope this is useful insight…

   05 Sep 2007, 21:49