Haptics and Ultrahaptics

Haptics and Ultrahaptics

From Disney to Microsoft, NASA to MIT, corporations and institutions large and small are increasingly reviving their interest in haptic technologies, whether pursuing the edge on the next generation of smartphones, adding a piece into the puzzle of augmented reality, or engineering a robot hand that can both collect soil samples on Mars and play the violin (albeit not at the same time). Yes, haptics are making a distinct comeback. And given the vast and increasing range of applications for such kinesthetic technologies we give it a big thumbs up. Why? Read on to find out!

Since the Dawn of the Internet – well, once we all got slightly bored of the bland screen of early classics like Pong – we have striven to create a virtual experience that is rich in content, eye-catching in color, and intuitive in use. From the early days through to the most recent revisions of classic user interface (UI) architectural theory such as ‘Don’t Make Me Think!’ the struggle to craft the best ‘look and feel’ has been real.(1) But the idea of a ‘look and feel’ has, in some ways, been little more than conceptual. Yes, given that the average user’s attention span is less than that of an already mated mayfly, the look is critical to keeping eyeballs on a page. But the ‘feel’ of a site, a game, or an app is something that’s more nebulous. We don’t really mean the touch sensation we get from flicking between Google results or completing forms for free HIIT workout downloads. We mean something a little more esoteric. Something that’s engineered in a cleanroom environment, added to a multitude of widely used and ultra-recognizable devices, but – to most of us – is fuzzy in terms of how the science actually works.

 

To date, we’ve tended to use holograms to convey a futuristic ‘feel.’ From popular TV series such as Star Trek, Red Dwarf, or even the early hit Quantum Leap, to movies such as Star Wars, Minority Report, or the adaptation of Dave Eggers’ novel A Hologram for the King, holography has played a significant role in communicating tropes of futurism. The semi-opaque, wavering holographic humanoid forms signal a future still ahead of us, one in which physical distance need not imply absence. And the next generation of quasi-nearness – virtual reality technology such as Oculus Rift – builds upon that concept in almost tangible ways. Note, however, that we use the word ‘almost’ very deliberately.

In the past – let’s say up until the cellphones smaller than an average house brick became the norm – it used to be that, when witnessing someone apparently connecting with things that weren’t there, we took action. A quick call to the emergency services would ensure the lone conversationalist enjoyed a secure ride to an even more secure facility until such time as they stopped communicating with Persons Unseen. But today when we overhear others talking into thin air, we just assume they’re running late to a business meeting.

And when we see random gesticulation as part of the conversation, we tend enviously to assume that their wearable tech is just so much better than ours…

Based in nature and perfected in the cleanroom, haptics and piezoelectrics are the new kids on the tech block.

And maybe it is. After a period of relative stagnation in terms of R&D, the field has geared up again, taking leaps forward in technology and miniaturization. So maybe that lone mumbler is not actually crazy but just packing the latest and greatest in remote communications tech. Based in nature and perfected in the cleanroom, haptics and piezoelectrics are the new kids on the tech block. And in a growing market set to be worth over $3billion by 2028, kinesthetic – another term for haptic – tech, for many of us, is found as close as our own bodies…(2)

Yes, look down at your wrist. See that Apple Watch or other smart wearable? That uses haptic technologies. Unless you change the default settings, the Apple Watch will employ tactile solutions as a way of notifying you of messages received, goals achieved, or incoming texts. Already so much more sophisticated than their predecessors – the Eccentric Rotating Mass (ERM) motors of the 1970s – the small vibrations generated against the user’s wrist let the watch give feedback or create subtle alerts without the interference of annoying chimes or other auditory notifications.(3) But this is only one style of haptic technology. In better understanding the field of human-computer interaction using touch-based communication it’s important to consider not only basic haptics, but also pietzoelectrics and ultrahaptics. Confused? Stay with us – we’ve got you covered.

Piezoelectrics – it’s an exotic word that basically just means electrical power generated from mechanical stress like pressure or sound waves.

And what is one of the most common substances that’s piezoelectric? Sugar! First discovered by physicists Pierre and Jacques Curie in 1880, piezoelelectrical technology leverages the ways in which the opposite sides of thin layers of crystals, when squeezed, will generate positive and negative charges.(4) This charge difference – aka voltage – can be relayed through a circuit, creating an end product of electrical energy from a purely mechanical initial interaction. Interestingly, the reverse circuit is also possible: where electricity is run back through a crystal it will expand and contract in size. So does this work with all crystals? No, not as such. For a material to be ‘crystalline’ it must be composed of atoms and ions arranged in formation. If this formation is an orderly matrix of ‘unit cells’ – a building block that repeats throughout the material with the atoms and units cells distributed symmetrically around a central point – the substance is not piezoelectric. But if the unit cell has no center of symmetry – like, say, a quartz crystal – it is a good candidate for working piezoelectric magic.

And in the natural world it’s not only crystals like quartz or silicon that have piezoelectric capabilities. Bone, silk, and even DNA all have the ability to turn mechanical energy into electricity and, having such a variety of source materials makes this technology attractive to a broad spectrum of applications – from medical imaging to inkjet printing. But it might be in computing and UX design that piezoelectrics can really find their home. Microsoft, for instance, has undertaken a significant amount of research into the use of piezoelectric stimulus in creating a new generation of touch screens.(5) Ones that not only allow data input via touch but also make the communication a two-way street, giving the user a tactile sensation in return.

How does this work? Phone screens that utilize piezoelectric actuator technology give the feeling of a button press because the screens flex just enough to mimic the sensation, offering a user experience that is much more affirmative than the audio confirmation currently used. And this has several advantages. According to Microsoft’s analysis, typing on a screen that has piezoelectric actuation is faster and results in fewer errors.(6) Moreover, users report that the sensation of a key press instills greater confidence in the character-by-character typing experience meaning less time is needed in re-reading for typographical mistakes.

Microsoft has created a way to leverage our body’s water content in creating the textile experience.

But let’s take it one step further. What if we wanted to create a touchscreen that offered a multi-textural user experience? This too is becoming possible. Using a combination of piezoelectrical actuation and electrostatic haptic technology, screens can give the sensation of stickiness/resistance or non-sticky smoothness when a layer of air trapped between the screen and the user’s finger is manipulated via vibrations. By adding a layer of transparent insulating material on top of the screen but below a protective coating, Microsoft has created a way to leverage our body’s water content in creating the textile experience. When charges are present in the conductive layer, the attraction of opposite charges creates a force that exerts a force upon the finger, pulling it towards the screen.97)

So a screen can now feel sticky or textured but a cynical mind might say that, even without advanced haptics and the like, careless use will generate the same effect. And also that stickiness on screens has no place in contamination-controlled environments! Moreover, in using piezoelectrics and electrostatic haptics we are still interfacing physically with a contact surface. Yes, it might be a very smart surface but it’s still a far reach from the holography we discussed at the top of the article. Enter a concept that has us incredibly excited to see where this branch of research could be headed: ultrahaptics.

If you’d had a passenger riding shotgun, the knob would have been invisible and you’d appear to be twiddling your fingers randomly in space.

Ultrahaptics is the science of creating the sense of touch in mid-air. Imagine you are in a car on the freeway. Maybe it’s one of those semi-autonomous ones with holographic technology we like to discuss here at Cleanroom-News? Unusually for this time of day – let’s say it’s around mid-afternoon and you’re intent on beating the craziness of the commute – you are moving along at a good pace, traffic flowing in all lanes and the radio reporting no major incidents ahead. You just have to capitalize on a perfect ride home like this so you shift forward to crank up some music. But instead of averting your eyes from the road in the search for a dial, a haptic knob appears under your fingers and you twist and rotate it in mid air. Songs from your drive-time playlist flood the car and you return to thoughts of a cold beverage when you get home safely again. If you’d had a passenger riding shotgun, the knob would have been invisible and you’d appear to be twiddling your fingers randomly in space. And if that person didn’t know your ride was equipped with ultrahaptic technology, it might have been the last time they ever accepted your Uber services again. Which, of course, might not be such a bad thing…

But a dial that appears in mid-air and can be twisted and turned?

How is that possible? The first step is for an array of ultrasonic transducers to emit sound waves with precisely calibrated amplitude and phase. Human skin responds to frequencies of between 0Hz and 500Hz and we experience the tactile sensation of these frequencies as resistance. When a host of sound waves is modulated to a frequency of between 200Hz and 400Hz and is emitted such that the sounds converge at a specific point in space (which we then penetrate) we experience them as resistance on our skin. In this way the convergence of modulated ultrasonics becomes an ultrahaptic dial and, as if by magic, music floods our car. Simple but mind-expanding, in the way that only the best science can be.

Incorporating ultrahaptic equipment and instrumentation into cars, trains, or planes will lead to increasingly lighter and more efficient vehicles.

And what is the future for this kind of technology? To be honest, at this point in time no-one can say for certain. All we do know if that the possibilities envisioned even two or three decades ago are now risibly simplistic and the sky literally seems to be the limit. Incorporating ultrahaptic equipment and instrumentation into cars, trains, or planes will lead to increasingly lighter and more efficient vehicles. Of course this has implications for our fossil fuel needs, our use of finite resources, and our lifestyle choices, as well as having global impacts on the climate. Augmenting reality, engineering humanoid robots to embark on space exploration in place of actual humans who would otherwise sign up for a one-way trip, or creating prosthetics with real-time sensory feedback for amputees – these are just some of the possible avenues of development. And with a more widespread adoption of the technology comes a reduction in product manufacturing overheads, followed by a lower price point that opens doors to otherwise unavailable markets around the world.

Plus let’s not forget, geeks that we are here at Berkshire, the unbelievable ‘cool factor’ of reaching out to twiddle a knob or change a dial that is composed purely of ultrasonic sound vibrations. You have to admit: that level of just pure ‘Cool’ is one reason we are so proud and passionate about Science!

Haptics, piezoelelectrics, and holograms – are you excited or do you see a dark underbelly to this technology? We’d love to know your thoughts!

References:

  1. http://sensible.com/
  2. https://www.idtechex.com/research/reports/haptics-2018-2028-technologies-markets-and-players-000596.asp
  3. https://www.boreas.ca/applications/
  4. https://ed.ted.com/lessons/how-to-squeeze-electricity-out-of-crystals-ashwini-bharathula
  5. https://www.youtube.com/watch?v=ee1wuZxiLsc
  6. ibid
  7. ibid

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