Haptics is the tactile feedback technology of simulated touch. Its name comes from the Greek word Hapitkos, meaning pertaining to the sense of touch. Haptic technology is about simulating the sensory input and feedback we receive from everyday real objects but in a virtual world. The technology does this by applying vibration and motion. The technology has huge potential in game development where users can fully engage with the virtual world and feel and touch their surroundings. Users are able to become their avatar.
Science learned from haptic research. This research helped scientists better understand how the brain controls our movements when preparing to pick up an object and controls the pressure used to exert force to control an object.
Touch is a very complex sense, and we use it and learn from it all the time, especially when learning motor skills that require very sensitive adjustments to tactile feedback. An example would be a simulation of a surgeon undertaking a procedure that involved direct manipulation of ligaments or tendons. The surgeon can watch a video of the procedure a thousand times and know exactly what is required, but until they can get to work on a real live tendon, they will not understand exactly how much or how little tension exists. They will have developed the intellectual and visual knowledge but not the motor skills required to undertake the procedure simply due to the lack of real world feedback in the medical simulation.
Haptic research in how humans interact with computers and virtual objects is still at a very early stage. Touch screens that act as virtual keyboards do not feel natural, so developers have tried to provide some sense of movement when an area of the screen is pressed. This is particularly important when designing systems for those with visual impairment as they cannot see the visual feedback and sometimes an audio feedback may be inappropriate, ie. when operating an ATM. This is where direct tactile research into haptic feedback is quite advanced. Several modern mobile phones, such as those from Nokia and Samsung, have advanced haptic feedback techniques built into virtual keyboards. Apple also tried to register a patent for a device that will provide localized vibration when touched. One of the potential, but not restricted to, applications was a touch screen keyboard.
What is apparent is that despite the highly adapted visual and audio feedback systems designed within computer simulation or virtual worlds, tactile sensory feedback is almost non- existent or extremely primitive. Gaming systems provide a very good example of this imbalance. Modern games have high definition 3D simulated graphics and audio, which are so highly advanced that they can even trick the brain into believing the simulation to be real. Yet, these convincing audio and visual virtual worlds still provide only a crude joystick or vibrating steering wheel for tactile feedback. Without tactile feedback, the human subject can never fully engage with the developer’s skillfully crafted virtual world.
This is what makes research and development into haptic technology so important. Humans have a rich and complex tactile sensory structure where each finger pad contains many different types of specialized tactile sensory receptors in both the skin and in the underlying tissue. These specialist tactile receptors, one for each type of stimulus, are triggered by light touch, heavy touch, pressure, vibration, temperature and pain. They feed the information directly to the brain, which helps it understand the objects and the world around us. By ignoring tactile sensory feedback the virtual worlds and simulators will always feel distant and unreal. Where motor skills are required such as in a medical procedure or the joystick control of a drone, then simulations will be intellectually educational but practically worthless.
Applications of Haptic Technology
As discussed in the previous section, computer and video game manufacturers are early adopters of haptic technology and the driving force behind research and development in the commercial world. Their desire to provide tactile feedback beyond the primitive vibrating joystick or steering wheel will be what drives the technology forward by funding necessary research.
Haptic technology though is not always well received. This was readily observable by the early tactile feedback innovators who developed user interfaces. By providing basic vibration in the typical range of electromagnetic components of 250-300 Hz, researchers discovered users found this a novelty which they soon switched off. The common complaint was that users felt the vibration annoying and further tests discovered that they preferred vibration in the 150 Hz frequency range.
Research and development has moved on since those 2nd generation vibration feedback systems, and currently, developers and research is focused on the production of 3rd generation haptic devices. This advanced research into haptic technology is reliant on audio and electrostatic haptics to deliver touch coordinated specific responses and customizable haptic effects.
4th Generation Haptic technology concentrates on the application of pressure on a surface and by varying the pressure to elicit a behavior and response. Currently, it’s not at a practical stage for commercial products or implementations. Fourth generation technology has been demonstrated with one system able to return three different responses dependent on the pressure applied by a finger on a flat surface.
The research today that could provide benefit in the near future involves the mastery of humans interacting with holograms and virtual objects.
The obvious beneficiaries of improved haptic technology would be the medical profession for tele-operations and training through simulation. The entertainment world of movies and gaming are also obvious candidates for early adopters as the ability to sense their surroundings and have a feeling of touch would greatly enhance the user’s sense of reality and facilitate their willingness to suspend belief. Whatever the benefits it brings, haptic technology will be the focus of extensive continuing research as its potential is enormous.