By Claire Swedberg
Oct. 17, 2008—Scientists at
GE Global Research, a division of the
General Electric Co., have developed a
high-frequency (HF) 13.56 MHz passive
RFID tag with an
antenna capable of functioning as multiple sensors. The group—composed of analytical chemists, polymer scientists, and RF and microfabrication engineers—has created several prototypes of the RFID multisensor for various applications.
The researchers have successfully used an
RFID interrogator to
read the
tag and its sensors' data. The new device could become commercially available in approximately two years, and could be employed for monitoring air, food or water safety, as well as for tracking the presence of chemical or biological contaminants in the surrounding area, or in a container's contents.
|
|
The GE sensor tag is smaller than a penny.
|
GE's battery-free wireless multisensor, however, would be a first of its kind, according to Radislav Potyrailo, a principal scientist at GE Global Research, and the leader of that company's wireless-sensor development team. Because GE's tag is battery-free and incorporates multiple sensor capabilities integrated on a single RFID
chip, he says, it can be made smaller than a penny.
The sensor-tag could be used by the health-care industry, Potyrailo says, as well as for security, food packaging, water treatment, employee badges and pollution prevention, to detect chemical or biological threats. It could, for instance measure the presence of bacteria in foods or beverages, or of other toxins that could be present in such substances as vaccines.
Battery-powered RFID tags already exist that provide multiple sensing capabilities. Such a tag would typically require an array of separate sensors, each wired to an RFID chip that then transmits the sensor data to an interrogator. In contrast, GE's multisensing tag consists of a passive HF 13.56 MHz RFID chip (compliant with both the
ISO 14443 and 15693 standards) with an antenna coated with chemically or biologically sensitive films.
"Our approach is to use the tag itself for sensing," Potyrailo says. "Thus, the tag still transmits a digital unique ID number but also becomes a sensor." For example, he says, to make it a gas sensor, the researchers would "apply a sensing film onto the tag antenna. With the deposited sensing film, the antenna becomes very sensitive to the desired gas."
The sensor's RFID
reader can obtain a number of varied responses for this device—several toxic gases or volatile organic compounds, for instance (as many as three concurrently)—so that a user can identify the presence and level of individual chemicals in different mixtures, and under variable conditions. These conditions could include temperature or humidity fluctuations.