New sense with new ‘skin’
By : Michael Gibb / Mirror Fung
The most widespread virtual reality (VR) and augmented reality (AR) systems currently create human experiences through visual and auditory stimuli. However, compared with the eyes and ears, the skin is the largest sense organ of the body. Therefore, the sensory experience can be greatly enhanced by using the skin to sense the external environment.
A skin like no other
A system of electronic skin-integrated haptic interfaces, or e-skin, jointly developed by CityU and other academic institutions can do just that. It can be used for social media, entertainment and gaming; help users of prosthesis to sense the surrounding environment; and develop virtual scenes for clinical applications.
The research has been published in Nature, a leading international journal, in an article titled “Skin-Integrated Wireless Haptic Interfaces for Virtual and Augmented Reality”.
Dr Yu Xinge (front row, left) and his research team at CityU. “Our target is to develop electronic skin that can be comparable to human skin,” says Dr Yu Xinge, the principal author of the article and Assistant Professor at CityU’s Department of Biomedical Engineering (BME).
“Compared with similar types of equipment on the market, our new system is light and thin, and can be tightly attached to human skin. Also, it’s wire-free and battery-free,” Dr Yu says.
The research team developed the system using new materials, device structures, power delivery strategies and communication schemes. And by employing sophisticated structural mechanics design, the new soft skin device, which is composed of more than 700 functional components, is less than 3 millimetres thick.
Low power, wire free and wearable
It works like this. The system transmits sensory stimuli to the body via wireless actuators that convert energy into mechanical vibrations. Different layers of the electronic skin include a thin elastomeric layer as a reversible, soft adhesive interface to the skin, a silicone encapsulated functional layer that supports a wireless control system and a series of interconnected actuators, and an external layer of breathable fabric, which can be put together with wearable clothes.
One of the challenges for the team was the wireless power supply and communication. A low-power wireless function was needed to significantly increase operational distance.
“Conventional actuators that provide sensory vibrations require about 100 milliwatts to transmit signals. However, we used radio frequency [RF] for power supply, which needs less than 2 milliwatts to transmit signals and produce the same level of mechanical vibrations,” Dr Yu says.
“So our new system not only saves power but also allows users to move more freely without the trouble of wires,” he adds.
Interdisciplinary, integrated and international
The research project, which took two years to complete, involves mechanical engineering, materials science, biomedicine, physics and chemistry.
“The biggest challenge was to integrate different technologies. Biomedical engineering is meant to invent something that used to be impossible for us,” Dr Yu says, adding that he is grateful to BME for providing the research platform and to Professor Sun Dong, Head of BME, for his substantial support.
Members of the research team comprised academics from Northwestern University, University of Illinois at Urbana-Champaign and Pennsylvania State University in the US, University of Bristol in the UK, and Tsinghua University and Shandong University in mainland China.
The project was funded by CityU, Northwestern University, National Natural Science Foundation of China and National Science Foundation of the US.