## 2 Problem Definition and Application of Haptic Feedback Technologies  
This section analyzes and classifies the existing typologies of haptic technologies and their use cases in different environments. \"Haptic\" derives from the Greek \"haptesthai\", signifying linked to touch sensation, commonly connected with adaptive connections to pass on or visualize items [23]. The tactile sensation can be described as unintended and dynamic. Hence, simple haptic devices such as remote controls, directional wheels, and gaming controllers are crucial.  
Haptic systems, also called kinesthetic correspondence or 3D touch, refer to any technical solutions that can implement touch by applying a few powers, vibrations, or movements to the user. In the last few years, several innovative haptic interfaces have been reported in the literature [23].  
The demand for haptic feedback technologies has increased due to the quick advancement of VR and AR. Especially with portable or wearable formats, these technologies enhance users' immersive experiences in a wide range of fields, including social media, entertainment, medical equipment, mechatronics, and more. The primary idea behind haptic feedback technology is to activate mechanoreceptors or afferent nerves beneath the skin with sophisticated actuators to produce a sensation or a feeling. Multi-modal pseudo-haptic feedback on replicated weight sensations in virtual reality has made some progress. Since VR has grown in popularity, it is crucial to give virtual items an accurate haptic sensation. Understanding the psychological impact of such feedback is still a work in progress [24].  
Ensuring greater rigidity and reduced inertia is a significant difficulty for modern tactile systems. Specifically, impedance-based systems are constrained by their high rigidity, whereas admittance-based ones are constrained by their ability to produce little inertia. As a result, it is challenging to reproduce both forceful touch and minimal inertia in virtual settings [25].  
To introduce sensing and feeling improvements by implementing interfaces for haptic feedback, a typical use case of such interfaces is the development of smart prostheses. Generating haptic feedback for smart prostheses is still quite difficult since they have trouble accurately gripping items when they do not have them. Recent scientific studies have employed several techniques to create haptic feedback. It has been demonstrated that vibrotactile feedback may be achieved by employing a compact and lightweight vibrator. The frequency restriction and the additional 400 ms delay are this method's drawbacks. However, the pressure feedback devices unavoidably increase the bulk of the equipment. Pressure feedback may typically imitate the pressure of the smart prosthesis-grabbing objects. Therefore, [PERSON] et al. developed the so-called Multimodal Fusion Transcutaneous Electrical System to overcome these problems [26]. This system uses various combinations and stimulation feedback with variable stimulus level, frequency, waveforms, and stimulating places to produce a multimodal stimulus haptic feedback. The  
Figure 2: Distribution of documents analyzed for realizing the survey of haptic technologies.  
stimulator has numerous independent channels and can create up to eight waveforms per electrode channel. To increase its dependability, it can connect to any device using Bluetooth 4.0 [27]. Nevertheless, under some circumstances, this could hurt and be uncomfortable for the amputee. Therefore, transcutaneous electrical nerve stimulation is the most practical way to produce multimodal fusion nerve stimulation (MFNS) when no stinging sensation is present.