NFC Light Up Rings | Cristian A. Guzman

Overview

The NFC Light-Up Rings were created as a companion to the Keyless Motorcycle Ignition System. Instead of carrying a physical ignition key, an NFC tag embedded in the ring could be scanned by the motorcycle's NFC reader to enable or disable the ignition. Since the ignition system uses NFC tags as "keys", I wanted to make my own rings that could serve as the actual keys instead of just using a simple card-sized tag. They're super convenient.

You can watch the full ring making process in this video:

This project combines a lot of manual fabrication, electronics, and art into something that can also be worn every day. The result is a very functional piece of jewelry ;)

Ring Construction and NFC Integration

The rings are handmade from thin strips of wood veneer that are softened, rolled around a cylindrical form, and laminated into a three-layer ring. A small NFC tag is embedded between the veneer layers, allowing the finished ring to communicate with an NFC reader while keeping the electronics hidden inside.

The rings can also be used with other compatible 13.56 MHz NFC readers, so their functionality is not limited to the motorcycle project.

Process to make the ring involves cutting, rolling and gluing the NFC tags to the veneer strip. — The process involves cutting, rolling and then gluing the tags to the veneer strips.

NFC ring on top finished blue ring. — This image shows the size of a single NFC tag and a finished ring.

I experimented with several types of wood veneer and found that some materials were significantly easier to form without cracking than others.

Before the ring is fully laminated, a "pocket" is cut into one of the inner veneer layers for the NFC tag. Once assembled, the tag becomes completely enclosed between the wooden layers.

A small external marker can also be placed above the NFC tag to indicate its position. I simply used the cut-off head of a small nail. This makes it easier to visually orient the tag toward the reader when scanning the ring.

A green ring worn on a one finger showing the mark which helps with orienting the ring. — In this ring, the small circular metal marker helps with orienting the ring towards the NFC reader.

After assembly, the ring is sanded to its final shape and finished with several thin coats of CA glue, producing a smooth surface while reinforcing the laminated veneer.

Illuminated Ring

Making the illuminated version was the most challenging variation.

In addition to the NFC tag used by the ignition system, the ring contains an NFC powered LED tag and two additional pre-wired 0402 LEDs (they're tiny!). Small holes and channels are cut into the veneer for the LEDs and wiring, and the additional LEDs are soldered directly to the LED tag before everything is enclosed inside the ring.

Gif showing the process of gluing one of the small leds to the LED NFC tag. — Attaching the pre-wired 0402 LEDs to the LED tags requires precision and patience.

GIF showing soldering iron touching the leads of the prewired 0402 LEDs connected to the LED tag on the ring. — Once the LEDs are glued to the ring, the LED leads are soldered to the LED tag.

Because the components and wires are extremely small, the soldering and alignment require a lot of patience. The assembly also had to remain thin enough to fit between the veneer layers without creating bumps in the finished ring.

GIF showing testing the NFC ring by bringing closer to a phone whose NFC feature is active making the LEDs light up. — Here, I was testing the LEDs by turning the NFC function on my phone, which makes the LEDs light up.

Before permanently sealing the electronics inside, the LED assembly was tested with an NFC reader to verify that all of the LEDs operated correctly.

Results and Design Variations

The finished rings function as wearable NFC tags and can be used with the Keyless Motorcycle Ignition System in place of a conventional NFC card or tag. Not only that, they can also be used with NFC enabled phones for other applications, such as opening links or triggering home-automation actions.

Close up picture showing rings of different colors spread out on a table. — These are some of the ring designs I made. The color combinations leave a lot of room to be creative.

Close up picture showing three ring colors: black, blue and green. — Definitely my favorite ring colors were the blue and the blue-green ring. So mesmerizing!

This project offers a lot of room for creativity, as the possibilities for altering the color, texture, and even the shape of the ring can be combined to generate countless designs using the same basic construction process. At this point, it becomes more of an art project, demonstrating the potential when art and engineering work together.