Part One: Q&A with Justin Patton, Auburn University RFID Lab
We recently spoke with Justin Patton, director of the highly respected Auburn University RFID Lab, to get his thoughts on the evolution of the technology beyond asset management and tracking to temperature monitoring.
Auburn University’s RFID Lab specializes in the business case and technical implementation of radio frequency identification technology in retail, supply chain and manufacturing settings. Launched at the University of Arkansas in 2005, the lab moved to Auburn in 2014 and continues to work with leading retail, supply chain, manufacturing and technology companies.
Q. How is RFID technology being used today for temperature tracking and monitoring?
Justin: There’s a branch of RFID which are sensor tags that come in all different shapes, forms and sizes. These tags can sense anything from temperature to humidity, to heat to shock, and to certain types of gases in areas where you want to make sure that there’s no gas contamination or whatever. But the most common type of sensor that everyone uses is the temperature sensor.
Temperature sensing tags typically involve a small battery-powered thermal sensor that goes on the tag itself. Then it saves the data that it scans from the environment around it. It’s often used in manufacturing metal materials, or inside autoclaves for heavy industry manufacturing. For instance, if you have carbon fiber parts that have to go into the oven to be baked for a certain period of time, you will want to know that it has been cured properly before you put it on an aircraft to make sure it has proper strength.
Q: RFID tags inside autoclaves can withstand that amount of heat and still function?
Justin: Yes. The nice thing about RFID, especially passive RFID, is that the tags are basically just a chip and an antenna. As long as you shield it properly, it will withstand huge environmental extremes. I’ve seen tags that are embedded in a ceramic cylinder that they use in smelting metal. Literally, these factories look like the end of “Terminator 2” and they’ll have RFID tags that go along with big buckets of molten metal that can survive.
Temperature tags are also used frequently with industrial-strength refrigerated glues, adhesives and solvents. You know how glue is, if you leave it out for a certain amount of time, it dries up and it’s not as sticky anymore. Which is not that big of a deal when you’re making macaroni art, but if you’re trying to glue together components to a heavy piece of equipment, it can be a safety issue. So they’ll place temperature sensors on the glue tubes to make sure that it’s not dried out and will still work.
Q. How about temperature monitoring of perishable food items?
Justin: On the food side, it’s the exact same concept except these sensors ride along with meat or produce or whatever it may be. Some of these tags actually have a tiny probe that you can stick into a meat product that will measure the core temperature. It’s similar to a turkey thermometer except it’s saving the data to an RFID tag so that whenever the shipment gets to where it’s going, you can automatically pull the data off of it without having to do any special interface with the item.
Q: So essentially, when you’re transporting meat or other food products, you can be assured that it stayed at the right temperature for it not to spoil or whatever?
Justin: So one school of thought for tracking these items is if a food product is not supposed to go over 40 degrees, for example, and it does go over, then it just pops a little red flag that warns you the item exceeded the maximum allowable temperature at some point. That doesn’t give you a lot of information. It just gives you a threshold.
The second way is to continuously log temperature over time, and that will help you with understanding where it’s been and when, the times and locations when it was more heated and less heated. If the temperature does rise over a certain threshold, then you can track how long it stayed over that threshold, when it went back under and try to track back the history of what happened. The tradeoff is that if you’re just trying to record that it went over a threshold, that’s a very small amount of data and it’s very easy to capture and transfer. But if you’re trying to capture many data points over time, then that’s a lot more data and it’s a little bit more complicated.
That concludes part one of this Q&A with Justin Patton, director of the Auburn University RFID Lab. Click here to continue on to the conclusion of this conversation.