# Integrated Haptic Feedback with Augmented Reality to Improve Pinching and Fine Moving of Objects
## 1 Introduction  
Hand gesture recognition plays a vital role in facilitating interaction and manipulation of virtual objects in virtual reality (VR) and augmented reality (AR) environments. In thephysical world, humans depend significantly on sensory inputs such as touch and vision to perceive and interact with their surroundings [1]. Translating natural hand interactions into VR and AR environments presents significant challenges, especially in accurately detecting gestures and sensing virtual objects. To tackle these challenges, researchers have developed various techniques, with one of the most notable being gesture recognition combined with haptic feedback. This approach aims to improve training effectiveness and enhance the sense of realism in VR simulations. These methods provide significant advantages in performing complex tasks, indicating that haptic feedback plays a crucial role in successful interaction recognition [2]. When haptic feedback is absent, users often report decreased satisfaction due to the lack of tactile confirmation, which undermines their sense of action validation and reduces overall engagement [3]. For example, surgeons have pointed out that the absence of tactile feedback is a significant limitation in virtual reality (VR) training systems. They often prioritize haptic input over visual cues, particularly when navigating delicate and concealed anatomical structures, such as those found in the brain [4]. Extensive studies have focused on exploring hand gestures and interactions with objects in VR and AR platforms, intending to improve control capabilities. Furthermore, advancements in haptic device technology have made it possible to recognize virtual objects through various sensory inputs, including motion, rotation, and other complex interactions. This evolution in haptic interfaces has significantly advanced human-computer interaction and, more generally, human-machine interaction, bridging the gap between the virtual and physical worlds by enriching tactile experiences [5]. [PERSON] et al. in [6] proposed a robotic manipulator with off-the-shelf vision-based tactile sensors on the gripper and a controller that delivers vibration feedback. Low-computation image processing converts tactile data into vibrations, allowing users to perceive applied pressure. Simultaneously, the controller translates linear and angular velocities into end-effector commands, ensuring a reactive and intuitive interface. In another study, [PERSON] et al. [7] integrated Prime II Haptic gloves from Manus with an Oculus VR headset. Since the gloves are not recognized as hands, they require attached Oculus controllers, making optical hand tracking impossible. The controllers send hand location data to the PC via the HMD, while the gloves transmit hand shape data via wireless connection. When a fingertip touches a virtual model, the computer triggers a vibration response, allowing users to touch, grab, and interact directly with virtual objects. [PERSON] et al. [8] used a compact bracelet device from Tasbi to simulate discrete events such as hand collisions, impacts, and high-frequency feedback. Their approach utilized these events to inform users about interactions with virtual objects. In addition, they employed proportional squeezing to convey continuous interaction forces. Another group, [PERSON] et al. in [9], developed haptic feedback patterns using ATH-Rings for virtual reality (VR) applications, providing vibrotactile and thermo-haptic feedback. The tactile sensor, equipped with a nichrome (NiCr) heater, is mounted on the inner surface of the ring, ensuring direct contact with the finger's skin. This design allows for precise monitoring of muscle swelling during finger bending while also delivering thermo-haptic feedback to the skin. In another study, [PERSON] et al. [10] introduced a wearable feedback interface to enhance ergonomics in heavy or repetitive industrial tasks.