How Smart Rings Work

Since very few smart rings are actually being sold, it's hard to know exactly what's inside these finger-mounted devices, but we do have some clues.

The backbone of every smart ring is Bluetooth technology. Bluetooth is a close-range wireless technology that allows any two Bluetooth-enabled devices to communicate with each other as far away as 328 feet (100 meters) [source: Bluetooth]. You've probably seen hands-free Bluetooth headsets that let you make cell phone calls without actually holding the phone. Like those headsets, smart rings contain a Bluetooth chip, which is really a small radio that can transmit and receive signals from nearby devices.

Like many Bluetooth-enabled devices, smart rings need to be paired with a smartphone to work. Once your phone recognizes and pairs with the smart ring, the two devices can talk to each other. Bluetooth makes it possible for smart rings to function as notification devices, and also as remote controls for Bluetooth-enabled devices and appliances.

Bluetooth is considered a low-power technology, but it still needs juice, so smart rings must contain some type of battery that can be recharged using a docking station or a wireless recharging pad.

In a futuristic twist, some smart rings use finger-pointing gestures to control Bluetooth-enabled devices. Point at the TV and draw a power button in the air to turn it on. Swipe your finger to the right to advance to the next slide in a PowerPoint presentation. For gesture-based devices, the smart ring must not only contain a Bluetooth chip, but also some kind of motion-sensing engine. The motion-sensing hardware and software detects the real-time position of the ring and sends that data via Bluetooth to the target device.

What you won't find on most smart rings is a screen. Yes, there are a few prototypes with a fingernail-sized display, but the whole point of a smart ring is not to stare at it like your phone. Without a screen, though, smart rings rely on smartphones as the chief way to program and interact with them.

That's why all smart rings comes with an associated smartphone app. The in-phone app is how you can customize the smart ring's settings and configure it to update you with notifications from other apps such as Twitter, Instagram, email and calendars.

One of the few smart rings that has moved beyond the prototype stage is Ringly, a fashionable gem of a device whose sole purpose is to deliver notifications from a paired smartphone. A woman wearing Ringly — the initial gemstone designs are marketed to women — can leave her phone in her purse and still feel connected to her most important contacts and social network feeds.

Ringly works by letting the user program the smart ring to deliver a custom notification for specific types of messages and also for specific contacts. Ringly can send notifications using four different vibration patterns and five different colors [source: Ringly].

Using the Ringly app, users can match one vibration pattern to text messages, for example, and another to incoming phone calls. Since not all calls are equally important, the user can further customize Ringly to blink red when the text is from her boyfriend or green when the phone call is from work.

The MOTA DOI SmartRing is a sleek device initially offered in bling-free white or black. Like Ringly, the SmartRing pairs with a smartphone and vibrates when the user receives messages or updates from his or her social media feeds.

Where the SmartRing differs from Ringly — and almost all other smart rings — is that it actually has a tiny touchscreen display. Along with a vibration, the ring displays an icon identifying the source of the notification. It can even display a short message, stock-ticker style, like a tweet or a calendar alert. Swipe right or left to toggle through your notifications. Its website says the product will also be available later in 2015.

Key to using both Ringly and the SmartRing is the intuitiveness of the devices' apps. The SmartRing's app isn't yet available, as of June 2015. But the Ringly app, free on iTunes and Google Play, is getting solid reviews. Under the "notifications" tab, you can assign different vibrations and colors to a long list of smartphone apps and functions: text messages, phone calls, Twitter, Facebook, Instagram, even Uber, the car service.

Here's where things get a little weird. Using a smart ring as a hands-free notification system that pairs with your smartphone seems reasonable enough, but do we really need to remotely control every device in our lives with our pointer finger?

The Japanese company Logbar seems to think so. In 2015, it started selling the Ring ZERO, a device that allows its user to control any number of Bluetooth-enabled devices with a series of finger-based gestures. To turn on the lights, you point at the ceiling and draw a light bulb in the air. When you take a picture with your phone, you can flick your finger upward to upload it to Facebook. Draw a bird in the air to send a Tweet or a music note to play a song.

While some people might think it's fun to play charades with their iPhone, the Ring ZERO is more of a parlor trick — or the awkward first draft of a future technology — than a truly useful device. Is it really any easier to draw a picture of a camera in the air than to click the camera icon on your phone? Plus, most smart rings are big and clunky, probably because of all of the motion detection hardware stuffed inside. And you usually have to take them off when you wash your hands [source: Campbell-Dollaghan].

If you have a hard time remembering all of the gestures required by Ring ZERO, good luck with Fin, a smart ring worn on your thumb. This device — no release date has been announced, and may never be — works by tapping the thumb against your other fingers. To skip to the next song on your iPod, drag your thumb across your other digits. To lower the volume on the TV, drag your thumb slowly down your pointer finger. To use Fin as a gaming controller, point your fingers at the screen and cock your thumb to shoot!

One smart ring remote control that actually exists is the NFC Ring. NFC stands for near-field communication, a radio protocol similar to radio-frequency identification (RFID) tags [source: Donovan]. The NFC Ring can communicate with any other device containing an NFC chip. For example, you can unlock your smartphone or tablet simply by sliding the ring along the back of the device. You can also unlock an NFC-enabled door with a tap of the ring.

If you're excited about the future of smart rings, we have lots more information about wearable technology on the next page.