Korea-based TEGway is developing ThermoReal, a thermoelectric array which can generate heat and cold with impressively low latency. The flexible nature of ThermoReal could make it suitable for integration into VR controllers, gloves, and more.

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:

Latency

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.

TEGway’s Thermoreal prototype device | Photo by Road to VR

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.

Our sense of temperature is not nearly as latency-sensitive as our senses of sight or hearing, but thermal haptics must still be fast enough to help our brains connect what we’re seeing with what we’re feeling. For many potential thermal haptic scenarios, it feels like ThermoReal has passed an important latency threshold that helps sell that illusion.

Amplitude

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.

Form-factor

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.

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They say it’s the “world-first ‘Stand-Alone’ high performance flexible [thermoelectric device].

– – — – –

For any good haptic device, figuring out how to use it is always the hard part. For ThermoReal, there’s a number of promising applications beyond simply making the player feel hot in a hot environment and cold in a cold environment.

As a few examples to get your imagination churning, the speed and amplitude of the temperature effects should be suitable for conveying the temperature of objects held in the user’s hand. That could mean, for instance, allowing the player to feel it when their energy-weapon has overheated, or feel the cold of a snowball when held in their hand.

The company also says the ThermoReal skin can create the temperatures in discrete areas, potentially allowing for the feeling of virtual objects moving across the player’s hand. You can imagine a sticky snail crawling across your hand, or possibly even larger creatures—like a snake coiling around your leg—if the tech was integrated into a suit-like device covering a larger portion of the player’s body.

Continued on Page 2: Lingering Questions »

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  • Andrew Campbell

    Can anyone explain how this works using the Seebeck effect instead of the Peltier effect?

    • Raphael

      Yes, Henry can.

    • Raphael

      Yes, Henry can.

  • Lucidfeuer

    Aren’t there easier way to imply temperature effects like TENS?

    • Raphael

      Yes, ice cubes and blow torch.

      • Caven

        Now, now, we’re not trying to extract information from a prisoner. :P

    • Setuping TENS is pain in the ass(or may be), because hardware has to have some certifications bacause it may be danger, and resistance of human skin varieties. Sorry for my english.

  • Lucidfeuer

    Aren’t there easier way to imply temperature effects like TENS?

  • Chris Gates

    Is anyone asking for this?
    I’m trying to get excited for it but…
    Of all the problems that need solving, this one is near the bottom of the list.

    • Raphael

      It’s only at the bottom of the list because you haven’t tried it even though you use it every fecking day of your life. Therefore I would say it’s pretty far up the scale just like body vibration feedback.

  • Eric Lotze

    To me this seems like warehouse scale vr might be the main market for this because of the software being more flexible unlike at home triple a games etc. Speaking of TENS, does anyone know what became of tesla suit? Their demo on dnews impressed me, but ever since ive seen nothing from them.

  • psuedonymous

    ” Exactly how much energy is required to achieve the levels of hot and cold that I felt is unknown to me. ”

    The Seebeck Effect is used in Peltier coolers, and this is essentially a Peltier on a flexible substrate. The power consumption is therefore (at a minimum, because efficiency is not 100%) double the energy removed from your skin, or a little more than 1x the energy imparted into your skin.

    For example, say you have a patch 10cm by 5cm, or 50cm^2. Say you want to keep power consumption below 1W (so your 2x 1.3v 2000mAh batteries can run it for a few hours). Thermoreceptors are about 0.2mm beneath the skin, and you are mostly water, so you need to heat around 1ml (1 gram) of water. To raise 1g of water by 1°C takes 1 calorie, or 4.2 joules. 1W = 1 joule per second, so you need ~4 seconds for every degree of temperature change per watt in this example, and double that for cooling.

    The thermal camera example shows about a 10°C drop in one second. For our hypothetical 10cm x 5cm patch, that would need around 80 watts of power.

  • Nice device and nice questions.
    Miniaturizing it can be far from easy, they should be completely integrated into a super-thin controller like the upcoming SteamVR ones.
    Companies like Magic Leap are struggling just because of miniaturization… so it’s something they should be really concerned.