Farsens, a technology startup founded by a group of scientists from the CEIT research center, is offering a portfolio of sensors integrated with passive ultrahigh-frequency (UHF) RFID tags that enable the collection of sensor-based data via a standard UHF reader.
Farsens currently has nine RFID sensor tags that it offers commercially. Each tag features a passive EPC Gen 2 UHF RFID inlay that supplies operational power to the sensor with which it is integrated. The types of tags that the company offers include those that measure humidity, temperature, magnetic field, pressure or physical orientation, or that perform some other action, such as illuminating a LED indicator light. All Farsens tags can be read via any EPC Gen 2 RFID reader. To do so, a user must first input specific memory access commands into the device in order to download the raw sensor data, and then perform certain mathematical calculations to convert that information into the appropriate units (such as converting the data into degrees Celsius, for Farsens’ Fenix temperature-sensing tag, or into gauss, for the firm’s Magneto magnetic-field sensor).
The latest tag in the company’s portfolio, being tested this year, is known as the Titan. The tag, which has an integrated relay switch, enables users to send instructions to the tag in order to open or close the switch’s electrical contacts. The tag is being trialed by several electronic-equipment manufacturers, including another RFID company, Premo Group, which uses the tag to wirelessly shut down power to a piece of equipment when necessary.
Farsens was launched in San Sebastian, Spain, in 2008, by Mikel Choperena, the firm’s product development manager, and an electrical engineer with a background in RFID technology; along with Daniel Pardo, the company’s general manager, whose Ph.D. thesis at CEIT was linked to sensor-based RFID; and Ibon Zalbide, Farsens’ research and development manager, another Ph.D. candidate from CEIT.
The nine-employee company develops technology that it intends to sell through systems integrators and distributors. Although it has multiple products now commercially available, they are currently only being trialed by a variety of end users—primarily manufacturers of electronic equipment. “System integrators use our [tags] to offer complete solutions,” Choperena states. In addition to the sensors, Farsens has developed and continuously updates sample software enabling RFID readers to download sensor data from Farsens’ tags and convert that raw data into units of measurement—such as millibars, for example, when reading the Vortex pressure-sensor tag—though most customers are expected to develop their own software.
“We provide the software for free for users to test the technology,” Choperena explains. “When users want to go further and develop solutions with our tags, we can provide them support with reader software development for their specific solution.”
The Titan, Farsens’ most recent addition to its product lineup, comes with an Omron relay that opens and closes a circuit based on instructions from the microcontroller, also built into the tag. According to Choperena, several electronics manufacturers are presently testing the Titan tag, using it to turn sensors on and off when a reader is in the vicinity. The Titan can be utilized to reduce battery consumption on sensors or other devices, by flipping a switch to the power when instructed to do so via RFID transmissions. In this way, he says, users can employ an RFID reader to periodically change a device’s activation status, thereby allowing that device to conserve battery life when not in operation.
Farsens’ customers will be companies that employ large numbers of sensor devices, but that want to reduce battery use by automatically switching those devices off at specific times, and then turning them back on when needed.
In a manufacturing facility, many battery-powered sensors are tracking such details as temperature, humidity, vibration or motion, and then transmitting that data via a Wi-Fi connection—but they do not always need to do so continuously. Since this may be required only at specific times, such as when a product being assembled is passing, the sensors could save battery life during periods when they are not needed. The Titan tag, Choperena says, could automatically prompt the tag to deactivate or reactivate a sensor’s power switch, by means of a reader mounted on an automated guided vehicle or some other piece of equipment.
First, the reader transmits its signal. The Titan tag then captures that transmission and sends back its own unique identifier. If software operating on the reader, or on a back-end server, recognizes that ID number as the one belonging to that specific tag, the reader proceeds to transmit a specific memory access command to either open or close the tag’s relay.
Choperena notes that a Wi-Fi-based sensor can expend battery power even when dormant, simply because the battery is connected to the sensor and turned on. “With Titan,” he states, “you have a segue between the battery and the sensor device, and the tag can tell it to open or close the segue.”
Hypothetically, a reader mounted on an automated vehicle within a factory could prompt the switching of the relay on a specific Titan tag, thereby allowing a sensor, for example, to collect data while that vehicle is within the vicinity. Another reader—perhaps on a following vehicle—could then switch the relay off again once the sensor data was no longer required.
There are numerous use cases for the Titan beyond the activation of sensors in manufacturing, Choperena says. For instance, the tag could also be used to activate or deactivate a lock attached to a container, providing access to the contents of a locked device only to those equipped with an RFID reader that recognizes the tag’s unique ID and then prompts it to open the locking mechanism. During a blood transfusion, for example, the system could be employed to ensure that blood placed within a box with a Titan-controlled lock would be given only to an individual authorized to receive that blood. Choperena also envisions its use in the railway and utilities industries.
Premo is presently trialing 500 of the Titan tags at its own facility in Spain to manage the operation of its own power filters connected to its manufacturing machinery, by turning off the machinery’s power supply, if necessary, by means of the company’s existing manufacturing area readers, says Ezequiel Navarro, Premo Group’s CEO.
“The performance, as far as the relay goes, is exactly the same as a wired relay,” Navarro says. But by enabling the relay switch to be triggered wirelessly, the Titan makes the system simpler than a wired connection, in which a relay would require a power source and an individual would need to manually control that relay—which also raises safety concerns, he notes. By switching the relay via RFID, Navarro explains, “it’s impossible to have an electric discharge” that could shock an individual, as might happen were the relay controlled manually. Premo intends to use a total of 5,000 of the tags by the end of this year.
A version of the Titan could be designed to include sensors, Choperena says, in order to collect data such as temperature or pressure, though the tag does not yet come with built-in sensors. “This is possible but is not developed yet,” he states.
Farsens is also developing a touch temperature sensor that detects temperatures only for material in physical contact with the sensor, rather than ambient temperature. This new sensor can include either a thermistor or a platinum (Pt) resistance temperature sensor, Choperena reports, and its main advantage is a wider temperature range. In general, ambient temperature sensors are semiconductors that can read temperatures ranging from approximately -20 degrees to +85 degree Celsius (-4 degrees to +185 degree Fahrenheit), he says, while thermistors can be used for temperatures ranging from -200 degrees to more than +600 degrees Celsius (-328 degrees to +1,112 degrees Fahrenheit). This new RFID tag would operate at 860 to 960 MHz, and be compatible with EPC Gen 2 commercial readers. The specific temperature sensor characteristics depend on the actual sensor to be used, he adds, while the sensor to be selected will depend on the specific application.