American Printer's mission is to be the most reliable and authoritative source of information on integrating tomorrow's technology with today's management.

Tracking RFID progress

Jan 1, 2004 12:00 AM


         Subscribe in NewsGator Online   Subscribe in Bloglines

Radio frequency identification (RFID) technology is, some say, set to become the new universally used method for tracking products through the global supply chain. Pundits believe that RFID's automatic identification and data-collection systems could make bar codes a thing of the past, especially if Wal-Mart doesn't back down from its mandate that all vendor shipments must have RFID tagging by 2005. Currently, RFID technology is considerably more expensive than bar coding. Privacy-rights activists, who fear the potential for RFID abuse, could also hinder mainstream implementation.

While it may be too early to comment on consumer acceptance of RFID, the technology itself is intriguing. Flint Ink (Ann Arbor, MI) established a new business unit, Precisia LLC, last August to develop conductive-ink technology. Conductive inks may be the catalyst for universal use of RFID tags — the technology offers a cheap method for producing the antennas required for tracking. We talked to Dan Lawrence, Precisia's director of technology and commercialization, and representative to the Auto-ID Center at the Massachusetts Institute of Technology (Cambridge, MA), which aims to create a global network of RFID for instantaneous data collection. Here he covers the basic principles of RFID, conductive inks and the potential impact on the retail supply chain.

What exactly is an RFID tag?

RFID tags comprise two essential components: a silicon chip and an antenna. The chip receives and transmits data, such as a product identification number, via the antenna. The data on the chips can be accessed by a radio frequency signal created by a “reader,” an electronic module connected to its own antenna and a computer network. The reader sends a specific signal to RFID tags in the immediate area. These tags then respond with an answer, again, such as their unique identification number, which the reader processes and conveys to a computer network. In this way, for example, a salesperson interested in knowing which and how many products are on a shelf can determine product availability in real time through a reader assigned to that shelf.

What is the difference between passive and active RFID tags?

RFID tags fall into three broad categories: passive, semi-active and active. Passive tags are the most simple and consist of the components described previously. They obtain power from the radio frequency field of the reader, and therefore don't require an integrated power source. This makes them the most inexpensive tag. Semi-active and active tags use an on-board power source to achieve either greater range or the ability to record data from a sensor. These tags are usually more complex and therefore cost more, although this can be offset by greater functionality.

Tags can also be read-only or read/write. Read-only tags are given an identification number that cannot be changed, but in most cases can be read multiple times. Read/write tags allow the data on the tag to be updated as necessary.

Give us an example of how RFID is being used today.

One of the most talked-about uses of RFID is in supply-chain management. With bar codes, a direct line of sight to the scanner is usually required to track an object through the supply chain. This requires time-consuming human involvement if, for example, there are 30 cases of product to scan on a pallet. With RFID, every case of goods on that pallet can be automatically recorded in seconds or less. Additionally, as products are placed on a store shelf, the system automatically updates the inventory and orders more as necessary. As tags become practical for individual products, out-of-stock items — a headache for both retailer and customer — will become a thing of the past. Auto-ID significantly reduces costs by allowing faster, more detailed inventory control.

What are conductive inks?

Conductive inks allow electricity to flow, letting inks act as wires, resistors or antennas. They may be composed of finely dispersed conductive particles, or more exotic materials such as conductive polymers. The inks are used to produce conductive patterns on both flexible and rigid substrates. Conductive inks serve as antennas for RFID, receiving a wireless flow of information from an RFID-enabled computer.

The most well-known application of conductive inks has been in circuit boards where using etched copper is not an option. Our efforts have been focused on using high-speed printing processes to print antennas for RFID.

Are antennas printed with conductive inks as powerful as traditional copper-coil antennas?

Precisia is exploring the use of inks in place of stamped or etched metal antennas at the various frequency bands used for RFID. We've seen that ink antennas compare favorably to copper at ultra-high (860 MHz to 950 MHz) and microwave (2450 MHz) frequencies. At high frequency (13.56 MHz), an additional processing step, such as elevating temperature or electroplating, can make ink work as well as coil antennas.

What are the benefits of using conductive inks for RFID?

One of the major challenges in the widespread use of RFID for retail solutions is cost. Today, RFID tags cost between $.30 and $.60 each. For luxury products that can easily absorb the additional $.50 per unit, RFID is an excellent inventory-tracking device. The search for cheaper tags, however, is critical for RFID use in lower-cost consumer goods. A $.50 tag on a tube of toothpaste, for example, is cost-prohibitive.

Conductive inks are cost-effective for RFID in two ways. The material cost of inks can be much lower than that of traditional stamped or etched metal antennas. Stamping and etching processes are considered subtractive, because they discard unused metal. Since high-speed printing processes are both fast and additive, applying a conductive ink antenna or circuit can be significantly cheaper and faster than the alternatives.

Conductive inks have traditionally been applied using screen printing. As a member of the Auto-ID Center, we are actively working with leading technology companies specializing in offset lithography, flexography, gravure and screen printing for conductive-ink applications. In January, Flint signed an exclusive agreement with R.T. Circuits to license its lithography technology for printing conductive inks. This is an important development because we expect many companies, particularly large-scale retailers, to ask suppliers to put RFID tags on products before shipping them.

What are ‘smart’ labels, and what role do conductive inks play in this technology?

Smart labels have functionality beyond that of traditional information labels. They may contain RFID tags, covert or overt brand-protection indicators, or sensors that alert the user as to the status of the product. Depending on the application, inks can be integrated to interconnect label components, act as sensor arrays and function as RFID antennas. Smart labels provide manufacturers, distributors and customers with real-time visibility in inventory, and can help monitor conditions and location anywhere in a supply chain.

What industries stand to benefit from these smart labeling and packaging technologies?

Smart labels can be used to monitor the temperature of perishable goods in shipment. Many packaged foods and pharmaceuticals must be stored and shipped at precise temperatures or risk contamination. A smart label using a special chip, conductive ink antenna and sensor would be able to gauge the temperature in shipment and alert a supplier to harmful shifts in temperature. There is also tremendous potential for smart-labeling applications for anticounterfeiting strategies, of particular importance to the pharmaceuticals industry.

What's in store for the future, in a world with RFID technology?

Precisia's conductive inks are already being used in RFID applications for smart labeling and packaging, and warehousing. They're also being tested for retail inventory.

Let's talk about the “smart” retail outlet of the future. Suppose a store shelf is nearly empty of a popular product. Today, a store clerk must notice the shortage and restock the item. With RFID, a computer could send an e-mail or page the clerk to alert her of the shortage. The store could then automatically notify the distributor and manufacturer of the product, requesting that more be shipped. Everyone benefits: the consumer (desirable products are available); the store (greater sales volume); and the manufacturer (better production scheduling, more accurate marketing and higher profits).