Phosphorescence-based temperature and tactile multi-functional flexible sensing skin

Skin-like sensors have attracted considerable attention in recent years owing to their important applications in intelligent robots, advanced medical equipment, and bionic technologies. However, most sensing skins are based on electronic systems that have many constraints and application limitations since their electronics-based structures have the disadvantages of complex structure, cannot withstand harsh environments, power supply needed, and so on. In this study, a transparent phosphorescence-based, flexible temperature-tactile multi-functional sensing skin was developed by arranging temperature-sensitive and mechanoluminescent microparticles in a polyimide. Based on the thermal-quenching of phosphorescence and mechanoluminescence, the temperature and stress signals are sensing wirelessly in the form of light. And due to the different phosphor materials, the temperature and stress signals are optically sensed and separated by wavelength. To enhance the sensitivity of tactile sensing, a unique sensor structure with protruding was constructed based on the tension effect of the polyimide solution to achieve effective tactile sensing. The temperature and tactile sensing functions of the skin were successfully demonstrated. In addition, its application to robot skin has also been verified. The current study shows the potential of the phosphorescence- based flexible sensing skin, indicating that it is a possible development direction for flexible sensing skin.