A Guide to Haptics

BACKGROUND

So what exactly is haptic technology? According to the International Society for Haptics, haptics in psychology and physiology are referred to as one's ability to actively explore the outside world - typically using touch. Though touch is not the only haptic feedback possible, "haptic touch" has often become synonymous with the term.

Today this term has evolved to mean "the science of touch in real and virtual environments." This includes not only the ideas of touch in relation to an organism, but also virtual environments currently being researched.

In essence haptic technology is attempting to become a metaphor for our real environmental feedback we encounter each and everyday.

THE PROBLEM

The idea of touch integration in technology is in parallel to the need for such touch sensor in our everyday lives. Think about it for a moment, how efficiently can you walk when your leg "goes to sleep"? Now imagine if your entire body were to "go to sleep" - exactly. That feedback is not only convenient, but necessary. Haptic feedback is so common in our lives that we often fail to notice, or appreciate its overwhelming necessity. Without it, such things as walking, handling objects, pretty much any physical action whatsoever would be greatly debilitated - if possible. Without feedback our muscles do not know how to compensate.

I will stop now to reiterate that haptic research is not for designing tactile sensors. Tactile sensors only sense touch, and then encode it into a digital sequence. Haptics is concerned with the reverse process - in essence the computer touching you back. Without this reversal of signal we are running our technology on a one-way path.

In technology, a need for a haptics is growing increasingly needed, for as its use becomes more and more prevalent in our everyday lives, a means of increasing efficiency needs met. Relying on one's eyes only is horribly inefficient.

Think about it. Why are our computer keyboards still purely mechanical? The technology exists that we could all have touch-sensitive keyboards - imagine how easy they would to be clean and their increased reliability! But the cost is much too great. Without feedback to our fingers, we are uncertain if we actual hit the key intended. Obviously, this feedback is done with little to no thought, nor visual inspection, but instead we rely solely on neural feedback loops and our Meissner's corpuscles for sensing.

True, people have become increasingly efficient at ignoring this need all together - take for instance the rapidity of some people's text messages via iPhone. Yet even this too isn't purely correct. Instead people are training the palms of their hands and the reaches of their fingers as signals for correct finger placement. Which, yes, does work to some extent, but the sensitivity of our fingers as compared to many other bodily parts - exponential.

Here is a physical representation of our sensory distribution:




The reality is, there are limitations to current strategies, predominantly of course that of our sight. These limitations can be overcome if we were to just better observe this oh so eloquent nervous system we already have!

Consider the blind for a moment please. Even without vision, much of the blind community can efficiently read with just their fingertips. If we can process and read information with just our fingertips (and brains of course), than why aren't we using such abilities to our advantage? As of now our fingers are stylus replacements. Developers make "touch-friendly" graphical user interfaces and we poke our way around, as it becomes more and more difficult to actually see where we are actually poking.

(consider the micro display I discussed in a prior blog: here)

THE SOLUTION

Researches should be developing an alternative to standard touch inputs - take for instance the blossoming multi-touch technology.

Mutli-Touch Gesturing



Granted, even though this technology is making huge strides, it still treats our fingers as if they were a mouse, not the complex input-output operators that they are. Ironically, enough it would not be a small stretch to say that even gaming controllers are slightly ahead of this curve, for these technologies enable the user to be completely engulfed in the task on the screen.

Regardless, as of now the easiest solution seems to be to keep our mechanical feedback found in our keyboards and controllers - which of course is how we've been getting by. Yet these inputs too could be improved. A number of companies are working on mechanical force feedback systems to give you a better sense of what you are feeling. I've attached two example videos below:

3D Controller Demo



Telepresence Demo




Yet even these designs have their limitations. The longevity of a mechanical device is almost always the limiting factor in a design - hence why all mechanical devices are measured by number of cycles. Thus even if such designs were made more efficient through lubrication techniques and better machining, they still remain the limiting factor. Yet even if we were to streamline manufacturing techniques that could give us reliability rates of years, one more major problem still remains - size.

The size of the mechanical feedback devices is often quite large - way too large to be used in a practical manner. The realm of microelectronics is growing at a much faster rate then micromachining. Consider the very computer you are reading this on - imagine if it still used all the mechanical parts that its grandfather had?

So how do we combat size? Well, we make our devices completely electronic of course. As of now, one of the most widely adopted haptic feedback mechanisms is the vibration that occurs (on some phones) when you press a button. Sure, this is a stride, well... maybe baby-step would be more accurate.

Vibration when pressing a button is about as useful itself as just pressing a single button. Which yes, of course this is better then pressing no button (or an imaginary button on your LCD screen) - but just one? This haptic feedback vibration relies upon existing technology that your phone already contains (which is ironically mechanical as well).

Regardless, there is no usable method from which to localize vibration to specific areas of such a uniform surface surface. And as long as we have LCD's, this will remain an issue.

Another option branching from my neck of the woods (in Biomedical Engineering) includes that of electronic feedback through neural stimulation. With advances and elctrostimulation techniques, small controlled current fields may be sent to one's fingers with results somewhat similar to that of you touching sandpaper.

A video of this work may be found below:



Yet even after seeing the advances made, the technology is still very much so in its infancy. The resolution of these 'tixels' as CEO Ville Makinen of Senseg calls them; they are still quite large - at the size of a single QWERTY button. He also noted an important point - the resolution of our eyes is much greater than our fingers, yet we must rely upon our fingers to do the inputting for us. Thus why not maximize our input capacities upon current technologies?

Ultimately, I feel that this technology, using electrostimulation, will be the future of haptic technologies. There has yet to be developed any other convenient, portable, way to bring this technology to an array of devices.

THE EFFECT

So what will this research bring for our future?

The answer is actually quite complicated. Succinctly, it will completely alter the way we interact with our electronic devices - resulting in much more efficient and immersive computing experiences.

Let us consider games. With such technologies in our games, these artificial worlds we've have created can become that much closer to real life. We will be able to truly engulf our audience in the action. They can feel the rifle kick or the grass scrape their legs. (Granted in such circumstances a true haptic suit would need to be developed to provide such an array of stimulations - which again reiterates the need for future electrostimulation research).

Similarly, this technology could be employed in video. Similar to a Disney World show, you could feel the wind blowing or the spider rub up against your legs. The technology could again completely immerse the viewer in the experience.

Consider virtual reality, and similarly augmented reality, applications. As I discussed here, augmented reality is at the forefront of immersing our two realities into one. Could you imagine feeling a brick, yet similarly feeling a digital image of a brick right beside it?!

If augmented reality were to incorporate such advances, the idea of our Internet world and our real worlds, will become evermore intertwined. As to whether this is a good thing, is always debatable. Yet to have a choice to take advantage of such an opportunity, to explore imaginary and real worlds alike, yes, of course, I think this could be a good thing.

Time. Time could prove a quite peculiar point of interest when such technology finally arrives. In essence, we could feel another time, a created time, a simulated time, or even a time at a readjusted rate. For instance, haptics could, be used to literally slow down actions that are to fast for us to normally see or feel. It could also be used in reverse to slow or increase the speed of our very actions.

For instance, take medicine - surgeons in particular. Doctors could wear special gloves that they use to control a robotically operated scalpel. Yet these gloves could be calibrated to operate at half the velocity of the surgeons hands themselves - thus literally slowing time for any given action. Such ability would aid greatly in precision techniques and operations.

In reference to medicine, haptic technology will also be employed for nerve-damaged patients. Through prosthetics, artificial limbs, and neural stimulator implants people may regain their sense of touch through very similar mechanisms. A computer and not the outside world will responsible for the final feeling the user gets.

This increase in accuracy could also be used just to overall our daily computing efficiency. Though our muscles are not optimized for using a single keyboard, our nerves are perfectly suitable for doing so. Yet again, more importantly than our ability to interact with our computers, is our computer's ability to interact with us. So how exactly does an interface feel? What about writing a word document or watching a video? These are very difficult questions. Some with no answers, though some that do.

Art for instance. Much artistic endeavor has moved to digital means for editing capabilities. Also, the precision and control on computers is much greater than that physically capable by both the human hand and eye. Yet as of now, most of these technologies of course have the one draw back of no force feedback. Drawing tablets such as Intuos Tablets have become wildly popular for drawers, for the sensation is quite similar to that of drawing on a piece of paper. Yet what about the painters, sculptors, and musicians? There are so many artistic endeavors that could benefit from such a feedback system. Imagine digital sculpting, or digital painting. Writing and performing digital music with something other than a piano keyboard.

I now wish to touch on the idea of sound. As I have discussed above, haptic technology is most readily being adapted to the sense of touch, though by definition - includes all feedback from the outside world. By definition, the very monitor from which you are reading this is a haptic device to your sense of sight, yet what about the other senses?

Touch is quite important, and one of the most obvious sectors to attack. Sound is typically transmitted with ease though sound playback technologies such as speakers, headphones, amplifiers, etc. Yet there is still a demand for such technologies in the medical world.

Cochlear implants attempt to transmit sound as neural encodings to be sent to the brain. This device is in essence a computer, attempting to communicate with our brains through sound. This haptic mechanism is far too often taken for granted, though improvements in the sector have come.

On a final note, haptic technologies should one day include smell and taste too. The ability to smell and taste the environment you are in is truly a wondrous idea - granted the obstacles that arise fall again in our realm of physiological understanding. How the body feels is relatively simplistic in comparison to trying to understand how the body encodes tastes and smells in our brains.

TO THE FUTURE

Haptic advancements will prove pivotal in our futures. From efficiency in our everyday computing to time-slowing medical procedure and new, immersive realities. The applications are extraordinary. Though inevitably, this too is just a stepping-stone, for our senses themselves are of course with limitations as compared to the processing abilities of the human brain.