Previously, Qingting.com reported on the low-voltage somatosensory solution jointly developed by City University of Hong Kong and Tencent Robotics X Lab. The principle is to simulate the sense of touch through micro-current stimulation, which can simulate the somatosensory sensation of tiny objects. Recently, a group of researchers from the City University of Hong Kong also announced a similar solution: WeTac, which integrates electrodes and flexible patches, which is claimed to be a "second skin" on the palm of the hand for AR/VR content. Bring tactile feedback instead of bulky motion gloves.
It is understood that WeTac is a wireless tactile interface system that can be used in VR, games, sports, skill training, social interaction, remote robot control and other scenarios to bring users a personalized and vivid tactile experience. The solution is soft, ultra-thin, and wireless, and can simulate personalized tactile data.
To put it simply, this solution is like a second skin, which fits the hand very well. It integrates the drive unit, hydrogel electrodes, and is packaged with an elastomer material. It only needs a small battery for power supply and can be charged wirelessly. , support Bluetooth connection. And the pattern of these electrodes is very cool, like some kind of personalized pattern.
Researchers said that existing haptic gloves mainly rely on bulky pumps and air ducts, powered and controlled by wires and cables, which hinders the immersive experience of AR/VR users. In contrast, WeTac has the advantage of being wireless, skin-friendly, and light in appearance.
In terms of details, the WeTac system consists of two parts: a miniature soft drive unit, which is connected to the forearm as a control panel. The drive unit weighs only 19.2g and is small in size, with a size of 5 cm x 5 cm x 2.1 mm. It can be attached to the arm without It will bring a lot of pressure to the user. It uses Bluetooth Low Energy (BLE) wireless communication and a small rechargeable lithium-ion battery.
The somatosensory feedback part is similar to the palm patch, only 220 microns to 1 mm thick, and 32 electrodes are distributed on the palm. The researchers call WeTac's electrodes electrotactile stimulation pixels, which are distributed on the fingertips and palms, with an average distance of about 13 millimeters from each other.
The advantage of using an electrical stimulation solution is that the electrode array can customize the intensity of tactile feedback, and can customize the experience according to different users. This is more flexible than more common solutions such as vibration and pneumatic, and solves a major bottleneck of current tactile feedback technology.
According to the team, WeTac exhibited great flexibility and guaranteed effective feedback in various poses and gestures. In order to verify the effect of hand tactile feedback, researchers tested people of different ages, genders, and jobs, and found that different people's hands have different tactile sensitivities, and fingers are more sensitive than palms. According to the experimental results, researchers have customized a threshold map for human hands. Through this map, users and developers can customize somatosensory feedback, and map tactile information such as pressure changes into a series of somatosensory threshold parameters.
The advantage of personalized somatosensory threshold is that it can allow electrotactile feedback to be delivered to any part of the hand on demand within the appropriate intensity range, without stimulating pain due to excessive intensity, or too weak to be felt. In addition, WeTac also has a number of built-in safety measures to protect users from electric shock. The temperature of the device is kept between 27°C and 35.5°C, so that the experience will not be affected by overheating.
In conclusion, WeTac is integrated with the skin as a thin and light patch, which can simulate the sense of touch by stimulating the palm with built-in electrodes. The distribution of electrodes is dense enough to not only provide tactile stimulation but also measure the user's sensory threshold in a flexible manner. By mapping the thresholds of different electrical parameters, the experience can be tailored to the user's sensitivity to touch, optimizing stimulation intensity and avoiding pain. In addition, WeTac can precisely control the somatosensory level, time and space perception. This technology is expected to provide a more vivid touch experience in AR/VR and human-computer interaction.
At present, researchers have verified the effect of using WeTac in VR and AR scenarios, and also achieved synchronization with the manipulator through BLE communication. Users can feel virtual objects in different scenarios, such as catching a tennis ball during sports training, touching a cactus, or feeling objects such as mice move on their hands. Reference: DesignBoom