Next to sight and sound, haptics are one of the lowest hanging fruits for creating immersion in VR. But beyond the rumble we have in today’s VR controllers there’s lots of other immersive haptic tech yet to be widely adopted.
Over the years I’ve had the fortune to see a wide range of VR haptic solutions ranging from the ‘amazing but impractical’ to the ‘simple and somehow unadopted’. Here’s a look at the five most interesting haptic demos that have stuck with me in the last five years.
A Joystick that Pushes Back
While it might be difficult to imagine how some haptic technologies could feasibly fit into a standard pair of VR controllers, the force-feedback joystick from Foldaway Haptics looks like a prime candidate.
Back in 2019 I got to demo the device, which takes the form of an origami-like structure that can tilt itself in any direction. The company has managed to make it work like a regular joystick for thumb input, with the added benefit of it being able to push or pull against your thumb in any direction. And further, what’s normally a single ‘click’ when you press down on a thumbstick for input can become a continuous press with varying force depending upon the situation.
I tried the prototype running with a Vive headset and a small demo game that Foldaway built. In the game I saw a miniature cartoon farm in front of me at waist height; a few different animals were running around on the ground. When I reached out to grab an animal, I pushed down on the thumbstick to ‘grip’ the animal between my hand and my thumb. Upon grabbing the animal, the thumbstick became stiff (letting me know that I had successful grabbed something).
Each animal had somewhat different haptic properties. The pig, for instance, was a little bit ‘squishy’, allowing me to push my thumb down on the stick a bit. The penguin was ‘harder’ so the thumbstick resisted my thumb much more. If I squeezed too hard, the force-feedback would give out and the thumbstick would bottom out until I let go (I expect this is to protect the motors and mechanism from damage).
Co-founder Marco Salerno told me that the current prototype is capable of pushing back with two newtons (about the force of two apples resting on your hand), though they could feasibly push upward of 15 newtons with some different design tradeoffs.
Beyond force-feedback just in the up and down direction, the joystick can also tilt itself against your finger rather than just pushing back. This allows directional information to be conveyed to you through touch, which is a big deal because the simple vibrating haptics in any consumer controller (VR or otherwise) cannot convey arbitrary directional information.
Directional haptics like the Foldaway device are especially useful compared to rumble because they can indicate a force in arbitrary directions, rather than simply an amplitude with no specific position or orientation (which is all you get with typical rumble).
A Simple Touch Goes a Long Way
In 2017 I saw a haptic demo so interesting that I wrote this headline (which I still agree with): Go Touch VR’s Haptic Feedback is So Simple You’ll Wonder Why You Didn’t Think of it First.
Call it ‘obvious,’ but this is the first time I’ve seen Go Touch VR’s approach to VR haptics, which provides nothing more than a variable force against the top of your fingertip using a flat piece of piece of plastic that moves back and forth with a little motor. Simple, and yet surprisingly compelling. The sensation is much like what you feel when you press your finger against a flat surface like a desk.
Typical controller rumble is widely applicable for shooting games where you’d expect a weapon to rumble in your hand. And yet in VR we also find lots of experiences where you aren’t shooting, but are instead grabbing, touching, and manipulating objects in VR which wouldn’t vibrate in real life, making it difficult to use rumble to convey meaningful, direct feedback.
It’s that grabbing, touching, and manipulation where Go Touch VR’s ‘VR Touch‘ haptics hopes to excel. Based on what CEO Eric Vezzoli calls a ‘Real Contact Sensation’ haptic approach, VR Touch is a simple, compact device which straps to the end of your fingers and provides nothing more than a plastic pad which can exert varying levels of force against the top of your fingertip.
That force can create a surprisingly compelling sensation of touching and grabbing objects with your fingers. Rather than abstract rumble, VR Touch gives the illusion of objects pushing back against your fingers directly.
The Go Touch haptic solution is fundamentally inexpensive given the way it works and seems like it would pair easily with a pair of VR gloves, or as a single module which would strap to the end of your finger to provide haptics and some input in conjunction with finger tracking.
Playing With Fire & Ice
Everybody knows that the best videogames always have a lava level and and ice level… in VR, what if you could feel them?
That’s where Korea-based TEGway hopes to come in with its ThermoReal haptics which made me a believer in the viability of thermal haptics for immersion when I first tried it back in 2017.
I’ve tried a few different thermal haptic devices throughout the course of my VR reporting, but nothing that really impressed me. Usually the effects are hard to notice because they don’t feel particularly hot or cold, and they take so long to activate that it’s hard to sell the illusion that the effect is being caused by something happening in the virtual world.
I got to try the ThermoReal thermoelectric skin at the Vive X Batch 2 demo day in San Francisco this week and it’s led me to become a believer in the value of thermal haptics for the first time. That’s thanks to three things:
ThermoReal—which is a thermoelectric generator based on something called the Seebeck Effect—is impressively quick to react. I held a prototype wand which had the ThermoReal skin embedded in it as I watched a video of a man jumping into a river. The moment he plunged into the water I could feel the wand get cold to the touch. Another video showed a car blowing up and the heat effect kicked in almost immediately with very little ‘spin up’ time. Keep an eye on the ‘thermal imaging’ section of the clip above to see how quickly the device changes temperatures.
In addition to hot and cold, the device can do both at the same time in close proximity, which is perceived as an amplified ‘pain’ effect compared to just using heat alone.
It isn’t just the speed of the hot or cold effect, but the extent of it too. I was impressed with how the device could achieve its maximum level of cold so quickly.
Even more than the cold effect, the heat effect was so great that I had to loosen my grip on the ThermoReal prototype at times; I was honestly concerned the device could burn me. I asked one of the creators if there was any risk of injury and was told that the device would only get up to 4°C hotter than body temperature. Based on how hot it felt, I’m still skeptical of that claim, though it’s possible that the rate of heat increase (rather than the measured temperature itself) could signal to my brain a more severe sensation of heat; I’ll be interested to learn more about the minimum and maximum possible temperatures of the device.
Thermoelectric generators like ThermoReal are not new. What is new, says TEGway, is the form-factor of their device. It takes the form of a flexible skin-like array of conductors which can be curved and wrapped around various surfaces, which could make it perfect for integration into VR controllers, gloves, or even suits.
The first ThermoReal demo I tried was just a static non-VR demo to show how quickly the thermal skin could change temperature and how that might be authored for content. By 2020 the company had built the tech into accessories for the arms, hands, and a VR headset.
The company showed a rudimentary but functional VR demo using the ThermoReal dev kit with an HTC Vive. In the demo, a character throws fireballs or snowballs at you; the gloves on each hand would respond with the appropriate temperature effect depending upon which was thrown and which hand you blocked the ball with. If the fireball or snowball hit you in the face, you’d feel the temperature on your face thanks to the forehead-mounted haptic unit.
The demo also demonstrated an interesting haptic effect which, while it made use of temperature differences, conveyed something different than simply hot or cold. In the demo you could expand a light shield on your hand which would block the incoming projectiles and disperse their energy across the shield. The glove and sleeve haptics responded by quickly alternating between hot and cold, creating a ‘force’ sensation that was really interesting; the feeling of hot and cold spreading rapidly over my arm created a unique feeling that could be used for more general haptic feedback than simply indicating which things are hot and cold.
Though the solution did offer a very interesting new dimension of haptic sensations for VR, expecting users to strap on additional accessories when jumping into VR is generally a non-starter for widespread adoption. As I concluded at the time: “it’s clear that thermal haptics would be much more viable if integrated into the things that VR users are already holding or wearing (like controllers and headsets). A separate ‘wearable’ accessory from ThermoReal would likely be relegated to non-consumer use-cases like training, rehabilitation, simulation, and maybe out-of-home VR attractions.”
Continue on Page 2: Directional Haptics with Simple Hardware »
Directional Haptics with Simple Hardware
In 2018 I got to demo a very unique haptic approach from a Japan-based haptics company called MIRAISENS:
The prototype 3DHaptics controllers from Miraisens do something that I didn’t previously think was possible. Being supported by nothing but your own hands, the unassuming prototype device uses vibrations to create sensations of an external force pushing or pulling your hand in specific directions. It isn’t a strong force, but it’s unmistakably directional. I closed my eyes and asked the demonstrator to choose random directions so I could guess the answer, and found that I was able to sense the intended direction with 100% accuracy.
The demonstrator ran me through a series of demos as I held the 3DHaptics prototype. After the simple directional demo, which allowed the demonstrator to point the device’s feedback at an arbitrary direction and amplitude, there was a series of examples using virtual springs which either asked me to compress or stretch a series of springs with one or two hands. The 3DHaptics feedback, combined with the visual feedback, was surprisingly compelling; it felt like the springs were pushing or pulling against my hands as I manipulated them. It felt almost like my hands wanted to move themselves in the implied direction.
What I found most interesting about this demo is that the hardware used to achieve it was dead simple. The company told me that each controller contained just two linear resonant actuators (LRA)… the same kind of haptic engine which is in many VR controllers today. Miraisens said the secret sauce that allows them to create an accurate sense of directional forces comes from the unique frequencies and waveforms with which they’re driving the LRAs. The company claims that the underlying tech is covered by several of their patents.
Holding a Virtual Object
There’s a lot of cool haptic tech out there, but to date the thing that’s given me the single most convincing sense of actually touching virtual objects has to be the HaptX VR glove.
As I explained at the time, the gloves provide two key forms of feedback:
First is pressure feedback, which aims to create subtle sensations of objects touching the user. For this, the HaptX glove uses arrays of micro-pneumatic actuators—effectively grids of little inflatable bladders which can be inflated and deflated quickly and precisely. By using the arrays to press against the palm and fingertips as needed, the glove can create a sense that an object is touching the user.
The second is force feedback, which is about pushing back or inhibiting the user’s movement in the same way that a corresponding physical object would. To this end, the HaptX glove has a mechanical brake on each finger which can prevent the finger from bending any further. For instance, when gripping a baseball, your fingers come in contact with the sides of the ball and are physically stopped by it. The HaptX glove simulates this by stopping your fingers from moving past where the point that they would stop if you were really holding a physical object.
With the two of these working in conjunction, I was blown away at how realistic it felt to rotate a completely virtual cube in my fingers:
HaptX just announced its latest version of its VR gloves, and though they are smaller than they once were, they’re still undoubtedly bulky and will likely be for some time to come. That means this kind of tech will really only fit in non-consumer scenarios where companies are willing to shell out for the added immersion.
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While there’s a lot of cool haptic tech demos out there—many of which can greatly enhance immersion—the unfortunate fact is that there’s various reasons why we don’t already see them widely integrated into existing VR devices. Often times it’s a matter of reliability, flexibility, power consumption, manufacturing complexity, miniaturization, or just outright cost.
With that said, haptics on VR controllers are at least making some advances. PlayStation is leading the pack in that department with PSVR 2’s new controllers which newly include force-feedback triggers. And Meta is getting more serious about controller haptics with its new Touch Pro controllers which introduce stronger and more precise rumble than prior versions.