Research progress in core materials of electronic skin and applications in field of life and health

Human skin can sense the information from the environment and play a significant role in the contact with the outside world. Electronic skins, which mimic the characteristics of human skin and the ability to perceive the environment have a wide range of applications in the fields of medical monitoring, bionic prostheses and robotic tactile perception. Compared with traditional wearable sensors, electronic skin is lighter, more flexible, more malleable, and has the characteristics of wireless, transparent, and compatibility with human skin, therefore, has become one of the emerging research fields. The electronic skin can continuously sense large number of physical and biochemical parameters of the human body, human motion and gas to monitor human health, sports condition and surrounding gases in various environments in real-time. In this review, the state-of-the-art of the materials used to making electronic skins, including zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) micro/nano-materials, polymeric materials, hydrogel materials and their composites, were discussed, and the practical applications of the electronic skin constructed based on these core materials were concluded in terms of health monitoring, motion monitoring as well as gas monitoring. It was pointed out that there are still some remaining technical problems in the research process of electronic skin such as high cost and complex process. The development trend of electrode skin was towards multi-function and simultaneous detection of multiple external stimuli, and it had broad application prospects in the fields of medical equipment robbotics and future manufacturing.