A touch of ultrasound
Controlling a TV set by pushing an invisible, yet tangible button in mid-air or projecting content onto a screen of mist - such futuristic technologies may find their way into our homes sooner than we think. First results of the EU-funded project INTERACT are already attracting a lot of interest from industry.
© Screenshot of youtube video by BristolIG
Just like the relatively recent advent of touch-screen technology, the technologies coming out of the INTERACT project could revolutionise the way we interact with and use electronic devices. But how can there be a sensation of touch, i.e. haptic feedback, without actually touching an object?
INTERACT project leader Sriram Subramanian of the University of Sussex, compares the effect to rock concert-goers feeling the vibrations of the bass speakers in their chest: “We are trying to recreate this experience, but in a more targeted way. At rock concerts, they play audible-frequency sounds for their audience to hear, but in the process the sounds are also making themselves felt. We, on the other hand, use ultrasound, which vibrates at a higher frequency. As a result, we can target it more precisely in such a way that you don’t hear anything, but you feel it a lot more clearly.”
The arrays that make this possible are composed of 20 to 200 ultrasonic transducers, similar to the ones commonly used in parking sensors for cars, for instance. The transducers emit high frequency sound waves, which create sensations on the skin of the hand when properly focused. But it is easier said than done.
“If you look at how waves propagate, every time they come into focus at a specific point, there are also many secondary focal points,” Subramanian explains. “If I put my hand up in front of a device and expect feedback at a specific location, there will be additional secondary points close by. Making sure that only the primary focal point is on your hand and that the secondary ones disperse elsewhere, was a big challenge for us. But addressing this challenge has meant we can now create many focal points on your hand to give you not only points but also shapes.”
Setting the industry abuzz
The idea of using speakers to create haptic feedback is not new. However, the INTERACT approach – which was not focused on one specific application, leaving room for potential customers from industry to come up with their own ideas – has kindled great interest from TV, laptop, smartphone, household appliance and car manufacturers alike.
The interest has been so great, in fact, that the project team set up a spin-off company called UltraHaptics in 2013, which has seen dramatic growth, especially over the past six months. The UltraHaptics team takes up where the INTERACT project left off, now working on bringing down the cost of the technology and making it commercially viable. At the same time, the company collaborates closely with a number of customers from different sectors to tailor UltraHaptics to their needs and integrate it into their products.
“We don’t know where that will take us,” says Subramanian. “Maybe after this joint development, one of them will say ‘okay, let’s build that product’. If that happens, optimistically speaking, such a product could be commercialised at the earliest by the end of next year or 2017. I was very honoured to obtain the prestigious ERC funding for this research, and I would be extremely happy if by the end of the INTERACT project, in October 2016, I could say ‘here’s the product on the shelf that you can buy’! But that is still wishful thinking at the moment.”
In the meantime, INTERACT has taken its visionary work on to the displays of the future, using mist, bubbles or even acoustic levitation, i.e. floating objects with the help of the same ultrasound speakers as the haptic feedback technology, hoping to bring those mid-air displays to the same performance level as UltraHaptics.