Engineering news
Unlike some other devices, which the developers said remain “typically bulky and tangled with wires”, the WeTac system is wireless and has soft, thin features.
With potential applications including gaming, sports and skill training, and remote robotic controls, the hand-mounted WeTac was developed at the City University of Hong Kong.
“Touch feedback has great potential, along with visual and audial information, in virtual reality (VR), so we kept trying to make the haptic interface thinner, softer, more compact and wireless, so that it could be freely used on the hand, like a second skin,” said research leader Dr Yu Xinge, associate professor in biomedical engineering.
Existing haptic gloves mostly rely on bulky pumps and air ducts, powered and controlled through cords and cables, which can hinder the immersive experience of VR and augmented reality (AR).
Instead, the WeTac system has two parts – a miniaturised soft driver unit, attached to the forearm as a control panel, and hydrogel-based electrode hand patch as a haptic interface. The driver unit weighs 19.2g, using Bluetooth low energy (BLE) wireless communication and a small rechargeable lithium-ion battery. The flexible hand patch is only 220µm to 1mm thick, with electrodes on the palm.
The device provides effective feedback in various poses and gestures, the researchers said.
“Electrotactile stimulation is a good method to provide effective virtual touch for users,” Dr Yu said. “However, as individuals have different sensitivities, the same feedback strength might be felt differently in different users’ hands. So we need to customise the feedback parameters accordingly, to provide a universal tool for all users.”
The softness of WeTac allows the threshold currents to be mapped for individual users, to determine the optimum parameters for each part of the hand. Based on the personalised threshold data, electrotactile feedback can be delivered to any part of the hand, across an intensity range that avoids causing pain or being too weak to be felt.
“In this way, virtual tactile information, including spatial and temporal sequences, can be faithfully reproduced over the whole hand,” the team said.
WeTac has reportedly been integrated into VR and AR scenarios, and synchronised with robotic hands through BLE communication. Users can feel virtual objects in different scenarios, such as grasping a tennis ball in sports training, touching a cactus, or feeling a mouse running over the hand.
“We believe that this is a powerful tool for providing virtual touching, and is inspiring for the development of the metaverse, human-machine interface (HMI), and other fields,” said Dr Yu.
The research findings were published in Nature Machine Intelligence.
Navigate a turbulent future by watching Aerospace & Defence webinars, now available to watch on-demand here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.