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Newsletter:  Dec 2001/ Issue 1
PNNL Receives R&D 100 Award for Radio-Frequency Tags

On June 29, PNNL received acknowledgement as one of this year’s recipients of the R&D 100 Award from R&D Magazine for its latest breakthrough in radio-frequency identification (RFID) technology. The system that received the award is a long-range, semi-passive radio-frequency tag that can identify, locate and assess the condition of items to which it is attached. The system significantly reduces the time necessary to locate, count, or monitor military equipment and personnel in the field, as well as commercial goods. The RFID system reduces the time necessary for high-volume inventory from days to minutes, and the location of specific items can be found instantly.

RF tags have been used for nearly twenty years for applications like identifying automobiles or lost pets and deterring clothing theft in retail stores. A basic RF tag consists of a small, electronic circuitry board containing an antenna, and stores and relays data. The device relies on modulated backscatter, which is similar to radio waves, and, as explained by Steve Stein, PNNL’s Smart Sensor System Technology Platform Leader, is “like a mirror in that it reflects back information” by bouncing back radio frequency energy instead of creating its own energy to communicate. Presently, there are three types of radio-frequency (RF) tag technology:

Passive RF Tags have no battery and are activated by an “interrogator” device, which transmits radio-frequency energy to read the information contained by tags. Passive systems have limited read and write memory that can be relayed to up to ten meters. The tags can be as small as a grain of rice, are inexpensive, and have a long operating life. Up to 500 tags can be read per second. They do not require line of sight and can be remotely monitored, giving them an advantage over bar-coding and similar inventory-tracking systems.

Semi-Passive RF Tags, such as the system which received the R&D 100 Award, use a battery, but still only reflect radio frequency energy to relay data. The tags can monitor sensor outputs such as temperature, pressure and tamper detection devices, use a watch-size battery, and have an operational life of five or more years. They are capable of activating or deactivating items remotely, can be read through walls, file cabinets and other barriers, and have a read and write range up to 100 meters. They offer highly efficient inventory control, detect security breaches, and can perform functions such as deactivation of a weapon if obtained by an individual without proper authorization. They can also assess whether an item risks damage due to surrounding physical conditions.

Active RF Tags are larger, more expensive and powerful, and rely on larger batteries to send and receive information. They initiate communication, have a read and write distance up to hundreds of kilometers, and can update and monitor information from other tags and systems. They can connect to multiple sensors, control valves and switches, and have decision-making capability. Active tags can be used for monitoring, real-time assessments, and notifications like providing an alert when mechanical equipment needs repair or replacement. Due to their reliance on a larger battery, self-activation capability and their possibility of being activated more often—even non-stop—active RF tags have a shorter lifespan.

According to Stein, PNNL is about two years ahead of commercial competitors in the RFID field. Lab scientists have improved upon existing circuitry making it more power efficient, enabling greater relay distance, and accelerating reading speed. Most of the customer interest in this PNNL technology so far has been from the defense sector.

Last November, a large-scale demonstration of a prototype RF dog tag was staged for the US Navy. The prototype was developed in collaboration with the Naval Aerospace Medical Research Laboratory in Pensacola, Florida with a $100,000 grant from the Office of Naval Research, which has funded much of PNNL’s research in this area. The tags are intended to serve various functions. They can store medical information like blood type and allergies, record treatment history, and transmit information on an individual's condition. They can also connect to global positioning systems to locate personnel and provide information to help coordinate the transportation of soldiers to medical facilities depending on the severity of their condition.

PNNL is also pursuing a RF sensor to monitor the temperature of the brakes of F-16s and provide an alert if the temperature surpasses operable conditions or renders the brakes unreliable. Scientists have even created RF tags small enough to attach to honey bees because bees pick up trace amounts of materials from their environment, including TNT released by landmines, which can alert soldiers to the presence of mines and facilitate their detection.

There are also numerous civilian applications for RFID technology, including supply chain management—enabling just-in-time delivery, asset management, security, and use in consumer products from appliances and automobiles to alarms and entertainment sensors.

“One of the challenges with this technology is that there is so much you can do with it,” says Stein. “It’s hard to focus on one application.”