Recent Progress of Skin-integrated Electronics for Intelligent Sensing

Detection of biophysical and biochemical signals deep in the body through the body surface is critical for health care. Current clinically available monitoring systems typically rely on heavy equipment that are not suitable for long-term and real-time monitoring of patients. Electronic devices with lightweight, flexible, and portable features are suitable substitutes for multiple biomedical signal detection. Therefore, flexible electronics have attracted considerable attention and gradually played an irreplaceable role in healthcare monitoring. Integrating flexible electronics with various sensing functions onto skin gives rise to the development of skin-integrated electronics. From physiological sensing, to sensory perception, as well as virtual and augmented reality (VR/AR), the skin-integrated electronics is presenting various intelligent functions.

In a new paper published in Light: Advanced Manufacturing, a team of scientists, led by Dr. Xinge Yu at Department of Biomedical Engineering, City University of Hong Kong, China reviewed and summarized the powerful capabilities of skin-integrated electronics from the perspective of intelligent sensing. Intelligent sensing is first reflected in the multi-functions of skin-integrated sensors for healthcare monitoring. The sensors are divided into two categories, biophysical and biochemical sensors, which detect all physiological signals from the body. Further, skin-integrated electronics demonstrate advanced intelligent sensing capabilities in artificial sensory perceptions, including visual, auditory, and tactile senses. Finally, skin-integrated electronics can not only passively detect external stimuli, but also initiatively endow feeling to the human body, which opens a new virtual reality (VR) mode. In recent studies, scientists have added tactile sense to VR. The sole reliance on visual and auditory senses will contribute to the advancement of the virtual world, gradually introducing new communication reforms, social media interactions, gaming, multimedia entertainment, and clinical medicine.

These scientists give their views and perspectives on the future development of these skin-integrated electronics:
“Novel functional soft materials are needed to achieve interfaces that are more comfortable and conformal with the skin to prevent delamination or irritation during daily use for on-patient healthcare monitoring. Furthermore, more effort should also be directed towards accuracy and durability of skin-integrated sensors.”
“Serving as the artificial sensory components for visual-, auditory-, and tactile-based sensations, skin-integrated systems contribute to the development of next-generation e-eyes, e-ears, and e-skin. Initial attempts of implanting skin-integrated electronics on artificial sensations are still in their infancy. Based on the platforms established by the current technologies, future research may consider developing high channel counts sensing pixels in soft electronics to significantly improve the sensory resolution or integrate various functional sensing systems. Moreover, it is extremely important to build neural networks that deliver external stimuli to the brain to obtain corresponding responses from the body.”
“Tactile sense in VR should be subject to further development in the future. In addition to the stimulation from electromagnetism-induced mechanical vibration, other type of stimulus deserves further research. The interconversion of different perceptions is another idea worth considering. For instance, a sound sensor and haptic interface can be integrated on the body of a deaf person. The haptic interface and auditory sense system can then convert auditory signals into tactile signals during conversations. Furthermore, the auditory sense system could translate the detected sound into visual texts to enable understanding for the deaf person, enhancing effective communication with others. Developing a novel integrated system that can intelligently select the use of different senses in specific situations would be challenging but also promising, because such a system considerably promotes the development of skin-integrated electronics in AR/VR.”

###