Wearables

RFID "smart" ring could replace cards, cash, keys and more

RFID "smart" ring could replac...
The prototype smart ring (top), alongside a regular ring for scale
The prototype smart ring (top), alongside a regular ring for scale
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The prototype smart ring (top), alongside a regular ring for scale
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The prototype smart ring (top), alongside a regular ring for scale
The RFID ring could be used to release electronic door locks
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The RFID ring could be used to release electronic door locks

It can be difficult, digging out your keys or wallet when your hands are full. Well, if an experimental new 3D-printed "smart ring" reaches production, such digging may no longer be necessary.

The metal ring is currently being developed by scientists from Germany's Fraunhofer Institute for Casting, Composite and Processing Technology, as part of the larger Kinematam project.

It contains a passive RFID (radio frequency identification) tag which gets wirelessly powered up by an electromagnetic pulse from a separate reader device. The tag proceeds to transmit a radio signal to that device, containing data such as a user-distinct passcode. Because the tag is powered as needed by the reader, it requires no onboard power source such as a battery.

The main body of the ring is printed in one tamperproof piece via a process in which a laser beam is used to selectively melt metal powder. As that powder melts in a predefined pattern, the metal particles fuse together, building the ring up one solid layer at a time.

During this process, a cavity is left inside of the ring. Before the print job is complete, it's paused in order to allow a robotic arm to insert the RFID tag into that cavity. The printing process then resumes, sealing the tag inside of the ring by printing a layer of metal over top of it.

Although materials such as metal can present a barrier to RFID signals, the layer over top of the ring's tag is just 1 millimeter thick, so it's not much of a problem.

Additionally, the tag transmits its data at a shorter-than-normal frequency of 125 kilohertz, allowing it to pass through the metal better than would be possible at a longer frequency. What's more, the walls of the cavity are designed to reflect the tag's radio waves outward, through the metal.

The RFID ring could be used to release electronic door locks
The RFID ring could be used to release electronic door locks

It is hoped that such smart rings (combined with onsite reader devices) could ultimately be used for tasks such as unlocking doors, paying for purchases, or even conveying vital medical information to first responders. The technology could also be used to manufacture "smart" devices other than rings, such as solid metal machine parts that transmit data on their operational parameters.

And if you like the RFID ring concept, you might want to check out the similar – and already-available – NFC Ring.

Source: Fraunhofer

4 comments
Mayhem
I have a bunch of friends who have implanted NFC chips in their hands. That seems like a way less cumbersome way to go about this. I don't wear rings or, frankly any jewelry that can be caught in or crimped by machinery or smashed by anything that I am working with (large rocks for instance) so having to clip a ring to my keychain and then remember to press it up against a door or what have you seems like a marginally better solution than a key...maybe. Implanted chips seem like a much better solution for people who need to work with their hands or keep their hands clean as possilbe.
Michael son of Lester
One thing that was missing from this article was the security aspect. Right now you can buy a handheld 10-Frequency RFID Reader Writer Copier Duplicator on Amazon for $65. So, how do they intend to protect the data stored on these rings from someone with a pocket-sized RFID proximity reader?
Username
@Michael The security concerns for this are no different than for "tap" credit/debit cards.
@Mayhem I agree with all you wrote!
Jeff7
Most people will just choose to have any of this built into a smart watch or phone (which almost every one has on them all day). Niche market.