# Touch, Texture and Haptic Feedback: A Review on How We Feel the World around Us
## 1 Introduction  
Touch is one of the most important senses in the human body. Touch serves as the primary means by which people interact with their environment. It is rooted deeply within people's everyday lives, from something as mundane and simple as turning on the lights to driving a car to work, nearly every interaction when broken down will involve touch in one form or another. Because of this, much attention and research has been focused on being able to capture and convey that feeling of touch.  
Haptics is described as the means by which information is conveyed through touch [1]. Currently many devices use haptics to convey information particularly through vibrations which is used to signify when new information is being expressed [2]. Beyond that, numerous other pieces of research have also been carried out in various fields to try and convey information through tactile stimulation with examples ranging from educational learning [3, 4], vehicular navigation [5, 6], military training [7], and physical therapy [8]. These methods, however, are rudimentary at best and are only capable of providing surface-level stimulation such as force and shape, especially when compared to the rich amount of detail that our skin is capable of discerning. Texture, for example, is a very subtle but powerful tool for conveying information. Different qualities such as roughness or smoothness convey different information which makes texture simulation an interesting but difficult topic.  
Recent advances in technology have greatly increased interest in haptic research especially with regard to virtual reality. Virtual reality environments provide an experience that normally cannot be achieved through regular means by allowing its user to effectively interact and sense objects through a combination of auditory, visual, and tactile feedback systems that immerse the user through the different forms of stimulation and interaction made through the simulated environment [9]. Currently, virtual reality is primarily used as a form of entertainment either through games or interactive media, with companies such asFacebook, Google, Samsung, HTC and many others investing millions in its research and development [10; 11; 12]. Aside from entertainment research and application of virtual reality, systems have become more widespread in a variety of different fields due to a large number of open-source software such as Unity3D and Vuforia [3; 13; 14] being available. Fields that have seen significant growth include educational learning [3; 4], navigation [5; 6], military training [15], architectural design [16], surgery [17; 18], and physical therapy [8; 19; 20]. Beyond virtual reality systems, augmented reality systems have also seen increased interest. Unlike virtual reality systems which have the user interacting solely with the virtual environment, augmented reality systems have the user interacting with both a virtual environment and the real-world environment through the superimposition of various virtual information systems to those of a real-world physical object and interacting with it as you would any other object [9]. More recent, augmented reality systems have also seen multiple applications in various disciplines such as in teaching [21; 22], surgery [23; 24], and navigation [25].  
The expanding interest in haptics is full of different challenges which will require different technology to overcome. The objective of this review is to present different technologies currently being used in the field of haptics and their strengths and weaknesses.