Dr. Patrick Fink leads technology development of radio frequency identification (RFID) systems. The RFID technology will support NASA's efforts to track its various inventories on the International Space Station, from personal supplies to equipment components. A new smart container innovation, developed at Johnson Space Center, tracks individual items, regardless of placement.
NASA Tech Briefs: How does your “smart container” enable the tracking of a collection of items?
Dr. Patrick Fink: The intelligence is actually in the packaging. The container has distributed RFID integrated circuits – the brains of an RFID tag. Then, those are enabled by a traveler. Think of a PEZ dispenser. A PEZ dispenser has a spring-loaded traveler that pushes the candies up. In [the smart container] case, a traveler enables one of multiple RFID integrated circuits. Software recognizes the correlation between any one of those IDs from the integrated circuits and the position of that traveler. From that, the processor can infer the level of items inside the container.
NTB: Can you take me through an example of a common use case for this technology?
Dr. Fink: The body reacts differently to medications in space. For the intended, original NASA application, some of the medical-support individuals on the ground wanted to take inventory and be able to track who has taken how many of each pill. The [proposed NASA] package would contain the intelligence to understand its inventory without having to tag each individual item.
NTB: From a technology perspective, how is it that individual objects don’t need to be tagged?
Dr. Fink: Instead of talking to tagged items, the RFID interrogator [or reader] is talking to a container. As a piece of the inventory, say a pill, is taken out, that spring-loaded traveler moves a little bit. Each time it moves, it enables a different, individual RFID integrated circuit. There also has to be an antenna embedded into that container; the antenna is only channeled to a select number of the RFID integrated circuits. Each RFID integrated circuit has a unique ID.
On the interrogator side, the software application sees that ID coming back from the package. By virtue of seeing which ID is responding, [the reader] can determine where that spring-loaded traveler is, from its full range of motion. In the pill case, maybe it’s reading ID #1, and then by the time all of the pills are removed, that traveler’s gone the full distance; now it’s talking to the integrated circuit at the other end of that travel range.
NTB: What is most exciting to you about the different possibilities of RFID technologies?
Dr. Fink: This all feeds into autonomy. It’s not just about humans knowing where the assets are. We are working with some companies to bring in new RFID technologies that allow very accurate localization. When that’s in place, machines can handle logistics. For example, on a precursor mission, the robots can unpack and set up structures, and have things prepared for human arrival because they know where assets are; they also know the assets’ orientation, which allows them to grapple with the assets much more efficiently.
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