April 2001

Inexpensive tape-based tags built into packaging could offer a new slant on consignment tracking

When somebody delivers an apparently unopened package to you, how can you really tell if it's been tampered with somewhere along the way?

That's just one of several puzzles addressed by a new development unveiled at this spring's PAKEX exhibition at the NEC. It was launched by packaging giant David S Smith, and consists basically of a kind of security-encoded tag (a tape, really) that can be embedded invisibly in packaging material. It can carry unique identifying information, and can be scanned remotely. David S Smith will be offering it as an add-in to its packaging products.

The new system, which has been branded iDent, aims to take on the functions of several different existing products ­ barcodes, radio frequency identification tags and holographic devices ­ and do it at an affordable price.

These various rival technologies offer their own attractions. DeLaRue Holographics had its own latest range on show at PAKEX, including tape threads derived from its expertise in producing banknotes; and its name is synonymous with the kind of holographic devices of course used on products such as computer software packaging.

Two-dimensional barcodes using Symbol's PDF 417 format are also gaining wide acceptance, offering the opportunity to encode quite complex information in an optically-readable format. And RF tags can allow information to be written to as well as read from concealed tags (see feature on page 28).

In the right applications, the iDent system is felt to offer advantages over all these systems ­ not least in price terms. Where RF tags are still struggling to beat the £1 price barrier, the iDent tape tags are expected to cost "a fraction of this amount" (perhaps 10 per cent, according to some reports).

The development has been a joint effort, in which the prime mover has been a Cambridge-based company called Flying Null. This is an offshoot of the Generics Group, an established design development company whose credits include digital payphones for Philips. The company has developed a magnetic material that can be produced in 2mm sq threads and applied to a flexible tape backing just one fiftieth of a millimetre deep. This can then be built into existing corrugated packaging. The company says the thread could also be embedded in plastics or carbon fibre products.

The tags can contain either an incremented code or a repeating "batch" code. Typically a uniquely-coded tag will require 30mm of the tape, while a repeating batch code can be incorporated in a shorter 19mm strip. The unique code consists of a seven-digit number, which is capable of referencing a large amount of detail. Manufacture is very strictly controlled to ensure security, and also (in the case of incremented codes) accurate registration.

The magic is that like RFID tags, the tape can be read remotely through any non-ferrous material ­ although ony at a scanning range of up to 50mm. So the contents of a carton can be checked without any external evidence of the contents. Moreover, if the tape is broken the code will not read, so there is a built-in tamper-proofing element. The codes can be read by either fixed or handheld scanning devices.

David S Smith acknowledges that the system is not a complete alternative to RFID tags. The tapes cannot be written to once manufactured, and they do not in themselves contain detailed or variable data. The codes embedded in them have to be referenced by look-up tables to provide meaningful information.

However, providing the circumstances of each data capture event are known, they can be tied up with the relevant information to build up a full audit trail for the product in question. Systems developer Microlise has already written software to handle the necessary look-up and analysis functions.

When you also take into account the low cost of the tags, they start to look an intriguing option for many kinds of single-trip applications.