Tactile technologies to take sense of touch to the Metaverse

Online shoppers will be able to feel products in the Metaverse thanks to a new system which allows users to touch virtual items and receive tactile feedback in real time.

The research team co-led by City University of Hong Kong (CityU) developed a wearable tactile rendering system, which can mimic the sensation of touch sensation with a resolution and response rate far greater than any previously developed. 

The team demonstrated its application potential in a braille display and claim the system could provide the sense of touch in the Metaverse for functions such as gaming and shopping in virtual reality environments. It is hoped the technology will help astronauts, deep-sea divers and others specialists who need to wear thick gloves in their work.

“We can hear and see our families over a long distance via phones and cameras, but we still cannot feel or hug them,” says Dr Yang Zhengbao, Associate Professor in the Department of Mechanical Engineering of CityU, who co-led the study. “We are physically isolated by space and time, especially during this long-lasting pandemic.”

There has been significant progress in developing sensors that digitally capture tactile features with high resolution and high sensitivity, says Zhengbao, but researchers still lack a system that can effectively virtualise the sense of touch and the ability to record and playback tactile sensations.

The team developed a novel electrotactile rendering system in collaboration with Chinese tech giant Tencent’s Robotics X Laboratory. Their findings were published in the scientific journal Science Advances under the title Super-resolution Wearable Electro-tactile Rendering System.

Electrotactile rendering system helps visually impaired

Existing techniques to reproduce tactile stimuli rely on mechanical and electrical stimulation, applying a localised mechanical force or vibration on the skin. However, they tend to be bulky, limiting the spatial resolution when integrated into a portable or wearable device. Electrotactile stimulators, in contrast, which evoke touch sensations in the skin at the location of the electrode by passing a local electric current though the skin, can be light and flexible while offering higher resolution and a faster response. 

The team ran different tests to show various application possibilities of this new wearable electrotactile rendering system. For example, they proposed a new Braille strategy that is much easier for people with a visual impairment to learn.

The proposed strategy breaks down the alphabet and numerical digits into individual strokes and order in the same way they are written. By wearing the new electrotactile rendering system on a fingertip, the user can recognise the alphabet presented by feeling the direction and the sequence of the strokes with the fingertip sensor. “This would be particularly useful for people who lose their eyesight later in life, allowing them to continue to read and write using the same alphabetic system they are used to, without the need to learn the whole Braille dot system,” says Zhengbao.

Researchers say the new system is well suited for VR/AR applications and games, adding a sense of touch to the Metaverse. The electrodes can be made highly flexible and scalable to cover larger areas, such as the palm. The team demonstrated that a user can virtually sense the texture of clothes in a virtual fashion shop and detect an itchy sensation in the fingertips when being licked by a VR cat. When stroking a virtual cat’s fur, the user can feel a variance in the roughness as the strokes change direction and speed.

“We expect our technology to benefit a broad spectrum of applications, such as information transmission, surgical training, teleoperation, and multimedia entertainment,” says Zhengbao.