Cut-price tag

A consortium of major European companies has started a three-year, £11m project to make Radio Frequency Identification (RFID) tags more affordable and widely available.

The MaDriX project team — comprising PolyIC, BASF, Evonik Industries, Elantas Beck and Siemens — will investigate the feasibility of high-performance, printable RFID tags. Currently, the tags contain silicon chips and are produced using complex manufacturing techniques.

For this reason, they are often used to track high-value products, such as white goods and vehicle parts. If the price of making them came down, however, they could be used to label off-the-shelf products in shops, such as everyday pharmaceuticals.

The team is confident that the cost will be reduced once the tags can be printed because electrically-conductive and semi- conducting plastics can be used in high-volume printing processes.

PolyIC has already unveiled PolyID, a polymer tag made from a plastic semiconductor called polythiophene. It is a passive tag that powers up when exposed to a 13.56MHz field from an RFID reader. The incoming RF signal provides just enough power to activate the integrated circuit in the tag and transmit a response.

The tag can hold between 32 and 64 bits of information, but this is some way off PolyIC’s 128-bit goal. At that size more data could be stored, making it competitive with silicon chip-based RFID tags.

But it won’t be easy to create a plastic chip that works as well as a silicon one. For one thing PolyIC managing director Wolfgang Mildner said it means adding many more transistors. And while the PolyID contains hundreds, its silicon competitor can contain roughly 12,000.

The company would have to miniaturise the transistors on its tags down to micrometers, and Mildner said this could only be achieved with a better semi- conductor material. PolyIC is currently working with BASF and Siemens to develop such a material as part of the MaDrix project.

Companies such as Philips are also hoping to commercialise a large-bit printable plastic RFID tag, but Mildner is quick to point out that his company was the first to demonstrate a 13.56MHz — one of the standard RFID frequencies —tag based on polymer materials in 2005.

The next challenge will be to increase frequency performance. Researchers have yet to develop a plastic chip that operates at the ultra-high-frequency of 860MHz to 960MHz, which would increase signalling range and could, for example, detect goods leaving a warehouse.

The frequency performance will depend on ‘mobility,’ or how readily the electrons move through a semiconductor in the tag. Mildner said he is confident that his researchers can demonstrate semiconductors with better mobility, but they will also need to demonstrate that they can be cheaply mass produced. Silicon-based tags are currently made for up to 8p each, but Mildner’s team aims to produce printable plastic ones for under 2p.

RFID could track pharmaceuticals through the supply chain, for example, providing extra information on where the product comes from and where it has been.

There have already been pilot programmes in the US that have demonstrated RFID tags tracking the highly-addictive painkiller OxyContin. The project, run by Purdue Pharma, demonstrated how RFID could not only help prevent counterfeiting but could also crack down on stolen and diverted OxyContin.

Purdue Pharma revealed that it invested £1m in the exercise and each silicon chip-based tag cost between 15p and 25p. A cheaper price could allow these projects to be expanded for commercial use.

‘With the pharmaceutical industry, the main concerns do not just have to do with the cost of production, but also the safety for the users of the product,’ said Mildner.