Haptic Technology

Haptic technology at action!

With haptic technology, a person typing on a touchscreen can feel as though they are typing on a physical keyboard

(By, Kevin Le)

In this current age, 3D movies are so common that it is hard to remember a time when movies when movies were not consistently made in 3D.  However, not so long ago, 3D movies were considered a treat, a thing of the future.  In some places, amusement parks such as Disneyland offer “4D” movies which blast the viewer with water, air, vibrations, and other expulsions to incorporate a feeling of touch as well.  Now, engineers are developing a new type of touch technology – haptic technology – where touching a screen or an electronic device will allow the user to “feel” various objects, such as fur or mud, in a virtual reality.  Most people will admit that touch screens are pretty cool – but flat, smooth touch screens that people can actually feel texture on is even cooler.

Haptic technology is meant to simulate the sense of touch in virtual reality.  To understand how haptic technology does this, it is important to understand how humans feel things.  When a person goes up to touch something, there are two different touch feedbacks which their brain interprets – kinesthetic and tactile touch.  Kinesthetic touch is how people actually touch things and how our muscles, tendons, and joints have to adjust to do something such as pick up a ball – it lets us know whether or not an object is big or small, far away or nearby.  Tactile touch is how people interpret various textures – it lets us know that a puppy’s fur is fluffy and that ice is cold.  All of this information is gathered by specialized groups of receptors called proprioceptors, located in the muscles, tendons, and joints.

Haptic technology imitates the signals being sent to the proprioceptors using something called force feedback, which takes into account both kinesthetic and tactile feedback.  According to Newton’s Third Law, every action force has an equal and opposite reaction force.  When a person touches something, they apply a slight amount of pressure against the object.  Due to Newton’s Third Law, an equal force pushes back, allowing the person to feel the texture, weight, and temperature of an object.  A common example of haptic technology using force feedback is in racing games – when the car bumps into something in the game, the controller vibrates in real life, thus allowing the player to “feel” the bump.

In touch screens, touch is simulated using the Coulomb force, which states that if there are two relatively non-conductive materials and a charge difference between them, then there will be a measurable electrostatic force pulling the two materials together.  In the case of many touch screens with haptic technology, high-voltage electric fields designed to give off frequencies the human hand is sensitive to run in a grid across the surface to generate the Coulomb force.  But do not worry – the voltage level is safe, and will not kill anyone.  So, when a person goes to feel a touch screen equipped with haptic technology, the electric fields will create different charge frequencies to attract the electrons of the person’s fingertip to different parts of the screen to simulate touch.  For example, if the touch screen is trying to simulate a surface with bumps in it, there will be a stronger and more attractive charge difference in the “bumps” than everywhere else.  So, when the finger swipes across the surface, the person can feel the “bumps” whenever the fingertip goes over an area with a stronger Coulomb effect.

Besides the obvious uses of haptic technology in electronics – particularly video games and phones – haptic technology would also be beneficial in places such as medical schools, where students could practice surgery without having to worry about messing up, since they would literally be able to “undo” their mistakes and try again.  In any place where touch is essential, haptic technology is applicable.  For example, using haptic technology, NASA scientists wishing to explore distant planets will not have to physically be there to “feel” their surroundings or know what is going on.  As haptic technology becomes more advanced, there is no doubt that it will become an integral part of technology in society.  Although that is only a prediction, it is important to note that sometimes the future is more palpable than it seems.

Posted in How Things Work