## 4 Overview of Wearable Interface for Providing Haptic Feedback  
Reproducing human touch is one of the primary goals of virtual reality research; thus, a significant part of the research aiming to improve touch perception is centered on sensory stimulation, avatar mobility, and avatar representativeness. The user is deeply engaged in the VR experience, regardless of whether changes impact their cognition, emotions, or bodily functions (interaction with objects, etc.) [47; 48]. From the need to recreate the interconnection with the surrounding environment for increasing the efficiency of biomedical systems, haptic interfaces were used to develop modern health instruments. Force feedback has been introduced and explored for teleoperation purposes, taking into account the many classes of haptic feedback currently accessible in several simulators and gaming interfaces. Furthermore, everyone agrees on the significant value of haptic force feedback in rehabilitative and therapeutic systems [49]. In grasping and manipulation tasks, where force feedback is an essential requirement, it has been demonstrated to lower their rejection ratio [50; 51] and improve the success rate [52]. Additionally, it reduces mental and physical stress and fosters a sense of embodiment [53; 54]. Through several techniques that may be generally categorized as invasive and non-invasive, much work is being performed to recreate this unusual, bio-inspired characteristic for impaired individuals [55]. [PERSON] et al. developed an innovative non-invasive wearable vibrotactile haptic feedback (Vi-HaB) system [56]. By allowing them to recognize and differentiate between specific fingers and different amounts of force input from the fingers to the upper limb, this device restores a disabled person's proprioceptive awareness. A plastic dummy hand integrates five force-sensitive resistors (FSRs), one on each fingertip. Five motor motors transmit force input to the user via these sensors. Three separate units constitute the Vi-Hab system: slave side, master side, and processing unit; the first includes five force-sensitive resistors (FSRs) and connects the master side and the surrounding world [57]. The processing unit converts the sensors' output voltages into the corresponding force intensities. To obtain the best resolution, the band was placed on the biceps region [58]. The wearable band has five equally spaced vibrational coin motors installed on the upper arm aligned with the fingers. Changes in the amplitude and frequency of vibrations are used to distinguish between different force levels. The frequency range of these motors (40 to 400 Hz) falls in the range of the Pacinian corpuscles, FA II-type receptors (Figure 8) [59]. A glove with multiple sensors and haptic feedback is needed for VR/AR applications and sophisticated robotics. Glove-based devices have the distinctive benefits of a high accuracy and multiple degrees of freedom (DOF) management functionality. These technologies, however, present several drawbacks for VR and AR scenarios. For instance, finger movement is a fine characteristic that vision and voice identification have trouble picking up. A smart glove with improved joint manipulation capabilities was proposed by [PERSON] et al. [34]; it comprises elastomer-based touch sensors and a PZT haptic stimulator actuator. This glove can be a supplemental control interface for augmented interactions for VR/AR applications and the existing visual and voice control interfaces (Figure 9). Sensors and actuators for multimodal movement detection systems and fast haptic feedback are included in a 3D-printed glove shell. The smart glove comprises finger-bending sensors to sense the movements of each phalanx with multiple DoF, whereas the palm sensor detects the shear and normal force in eight directions (Figure 9). Hemispheric-shaped triboelectric sensors were made with the Eco-flex elastomer.