The last demo I had during my CES in January wasn’t for sure the least in terms of importance. I was able to go hands-on with Afference, a very special ring meant to give haptic sensations. Why was it so special? Well, let me explain to you…
Afference Ring and the referred sensations
Afference is a startup proposing a haptic ring. It is a ring that you wear at the base of your finger, and through electrical stimulations, it can provide haptic sensations to that finger. The ring is connected through Bluetooth to the device where the application that needs haptic sensations is running, may it be a computer, a phone, or an XR headset, and then the application can stimulate your finger any time a haptic sensation is needed. So, for instance, if you have a virtual UI in an AR application running on your glasses, Afference may make you feel a haptic sensation whenever you press a virtual button, for added realism to the interaction.
Most of the time, what you need is haptic on one single finger, like the index finger through which you interact with the menus, and in fact, the demo at CES was about stimulating only the index finger. But the vision of the company is potentially giving you haptic sensations on your whole hand, and in fact, it showcased a mannequin hand with a sort of Afference glove featuring a ring for every one of the five fingers of the hand.
I still owe an explanation of why this ring is so special: well, the fact is that while the ring is installed on the base of your finger (like every ring), you feel the haptic sensation on your fingertip. The ring stimulation is not vibrational, but electrical, and thanks to some neuroscience magic that is the specialty of this company, the ring can cause a phenomenon called “Referred Sensation”. This means that while the actual stimulation happens at the base of your finger, you feel the sensation at its tip. This approach brings the advantage that you can feel sensations on your fingertips without having the fingertips covered in sensors or actuators, leaving so your fingers completely free to operate with the world around them, touching and grabbing objects.
This is very cool, and that’s why in 2024 this product won an Innovation Award at CES. But does it work? This is what I tried to discover during my hands-on session.
My hands-on with the Afference Ring demo
I had my hands-on session with the Afference ring in a suite at the Venetian Hotel in Las Vegas. There I could try the device without the typical rush of the CES showfloor. The team was very kind to host me and to let me try the device (thanks, guys).
I could put on a single ring on my index finger. The ring looked like 3D printed (and this shows they are still iterating the product). Even if ideally the ring should be connected via Bluetooth, during the whole demo they kept it connected via USB: this is because there are so many demos happening at CES that interferences are very common, so they preferred going for the safe route and using a cabled connection. This was not a problem at all during my demo.
The demo started by choosing the best ring size to fit my finger. Then we started calibrating the device. Like with many devices providing electrical stimulation to the body (e.g. OWO Vest, or Teslasuit), the team made me feel an increasing level of electricity and I had to tell them first of all when I started to feel some sensation (this was the low threshold) and then when the stimulation was too strong and was becoming painful (this was the high threshold). After the system was calibrated with my comfort levels, the demo could start.
The demo was not happening with an XR headset, but simply with a laptop featuring a touchscreen. They started by making me see some bubbles on the screen, and I had to pop them using my fingers. After I popped a few bubbles in a standard way, they activated the haptics on the ring and made me try again. This time every time I touched a bubble, I could also feel some electrical stimulation. The demo went on with other similar mini-applications, like for instance a minigolf game, where I could feel a haptic sensation every time I touched the ball, and a stronger one every time I won.
I had mixed feelings during this first demo. On the good side, the haptic sensation made the experience more interesting: it’s always cool when your hands can feel something every time there is an interaction, it makes the experience feel less flat. And it was great that I could feel these sensations while still operating on a touch screen: this is the advantage of having haptics via a ring and not via something installed on your whole hand like a glove, which would have prevented me from using any kind of touch device. On the so-so side, while it was true that I could feel sensations on my fingertip, I could also feel it irradiating from the ring position. So I could feel the classical tingling of electrical stimulation (if you have never felt it, imagine it like many needles touching your skin), that went all over my finger, from the base to the tip. This is not exactly what I was expecting. On the bad side, there was the fact that notwithstanding the calibration, the stimulation was somewhat uncomfortable: it was like having little electrical shocks to my finger. When the sensation was delicate, it was just a little nuisance, but when it was stronger, it was uncomfortable (but still not painful). For instance, there was a strong sensation to signal my win at the minigolf game and it was something that caused me discomfort, so in the end my brain did not want to win the game not to feel this sensation. Another bad consequence is that after all these electrical stimuli, my finger felt like “tired” of receiving them. It’s hard to explain this sensation, but it is like I needed to take a break because of the too many electrical vibrations I had received.
Electrical haptic stimulation requires very accurate fine tuning to work well: I still remember when I tried the OWO Suit and the stimulation was so strong that after 15 minutes of demo of receiving electrical stimulations all over the torso, I had to sit down to recover a bit.
My hands-on with the demo 2.0 of the Afference ring
I reported all the above feedback to the Afference team and they offered me the opportunity to try version 2.0 of their demo. In this new demo, an Afference employee was at a laptop and was able to stimulate my finger with specific haptic patterns. This is the demo you can also find in the YouTube video that I shot with Afference at CES.
This demo started again with a calibration phase and then I wasn’t able to do any interactions, but I just had to wait for the Afference employee to stimulate my finger with different patterns, like a sinusoid, or a spike.
While this demo was more “boring” because less interactive and felt more like a technical demo, it was much more interesting to me. First of all, I felt less discomfort: I don’t know if it was because of some algorithmic improvement or because we did a better calibration, but trying these haptic sensations was more pleasurable. Then, the sensation was more like it was intended to be. There have been some patterns where I felt the haptic stimulation only on my fingertip. When it worked, it felt like black magic: I could feel almost no sensation around the ring, and then I could perceive the haptic vibration almost only on my fingertip, even if there was nothing around it. I could perceive perfectly the haptic pattern, with its ups and downs, as if something was touching the tip of my index finger. I was surprised by it because I could not believe it could happen. It was fantastic.
Even with this demo, the haptic sensation was not exactly like touching a real object, though. It was still an electrical sensation, like a tingle, like being touched by needles. I asked the Afference team about this, and they told me that recreating a sensation like physical pressure with electrical stimulation is very difficult and so it is not the current purpose of the company. For now, they are focusing on giving haptic sensations, a sense of touch, something more suited for abstract interfaces, like interacting with the buttons of a UI. Long term we can dream, but in the short term, this is what they can realistically do. They told me that AR glasses are for them the ideal target hardware because you could operate with virtual UIs and feel some sensations when you touch buttons and still have your fingertips free so that your hands can operate normally with the world around you.
The safety of the device
To end the demo stupidly (I guess I watched too many episodes of Jackass in my life), I asked them to give me a big electrical shock to the finger (you can also see that at the end of the YouTube video). When they did it, I felt pain, but then I checked my finger, and I had no consequence whatsoever: no remaining pain, no burnt area, no consequence in my ability to move it. This means that the technology is safe to use: even when used at a higher power than the calibrated one, there is no risk for the finger to be damaged.
Final impressions
I came out pretty impressed by my demo with Afference, especially with the second one. When the device works, it feels like magic: you feel haptic sensations on your fingertips even if you don’t wear anything on your fingertips. This is just… wow. But at the same time, I think the team has still to work a lot on it, especially on its two current major issues. The first one is that this “referred sensation” should happen every time and not only sometimes: it should never happen that I still feel electricity around the ring. The second one is that the haptic sensation should never feel uncomfortable, and should feel less like “needles” and more like “a gentle caress” on the fingertip.
If the team manages to make this ring work all the time like the few times where it worked perfectly and I got super excited about it, I think this technology can for sure be part of the future of augmented reality. I think rings could be a great way to interact with AR glasses without having to always move your hands in front of the device (which could make you look ridiculous outdoors) and if rings could also have haptics instead of just touch interactions, they could be very functional as an input device.
For sure I’ll keep an eye on Afference for the future and I truly hope to try an updated version of this device next year. I wish the best of luck to this talented team.