Coca-Cola's Freestyle is a prime example of the new breed of RFID applications. The machine, in development for more than four years, is essentially a self-serve fountain. Operating like the beverage world's version of an ink jet printer, it allows users to mix and match drink ingredients. From it, they can order a Coke with lime, lemon, or even papaya flavoring. In all, they can select from 100 possible brands, including a variety of waters, juices, teas, and sparkling beverages. (Coca-Cola did not respond to calls for more information.)
By employing RFID, Freestyle is able to perform functions unlike any previous beverage machine. Using RFID tags and a permanent reader, it immediately "knows" each cartridge and recalls when it was plugged in. It can track the amount of liquid dispensed and can predict usage rates and inventory needs.
"It's cool," Stelter says. "It's a perfect example of what none of us envisioned five years ago."
Indeed, no one envisioned such applications. Then again, no one knew five years ago how far RFID technology would come. Suppliers say the advancements in readers, chips, and tags (which hold the chip and the antenna) have improved on multiple fronts. System sensitivity has vastly increased, power consumption is down, and prices have dropped to the point where retail outlets can benefit from using the technology on a high-volume basis.
RFID chips, such as Impinj's Monza 5 devices, are dwarfed by a penny. Each tiny black square on the wafer in the background is one RFID chip.
Sensitivity and power consumption are especially important, say engineers. The technology's modus operandi is simple: A reader sends out an RF signal to the tag's antenna. The tag, which has no independent power of its own, scavenges energy from the signal. When the RFID chip turns on, it modulates and reflects the signal, thus communicating its stored information with the reader.
"Chips have become much, much more sensitive," Stelter says.
One reason for that is the inexorable progress of silicon semiconductor chips. A key measure of that is transistor count, engineers say. Impinj's miniscule Monza 5 tag chip, for example, now incorporates twice as many transistors as Intel's early 8080 microprocessor from the 1970s. As a result, RFID chips read faster, write faster, and have more memory.
Antennae are also responsible for the improvement. By graduating from copper to other materials, including aluminum, antennae have enabled tags to become better at communicating with readers.
"We've seen huge strides in readers, chips, and tags, right across the board," Mitchell says. "The technology has matured tremendously."