Research progress of waterborne polyurethane-based flexible sensing materials

In recent years, flexible sensors have a wide range of applications in wearable electronic devices, healthcare devices, electronic skin and soft robots. Polyurethane (PU) is a class of basic materials used in the field of flexible sensing, with the advantages of elastomer-like, flexibility and compatibility, which can meet the demand for better stretchability, higher sensitivity and wider working range of flexible sensors. However, with the increasing awareness of environmental protection, waterborne polyurethane (WPU) has become a research hotspot in the field of flexible sensing by virtue of its environmental friendliness, low volatility, and ease of handling. In this paper, the recent progress of WPU-based flexible sensing materials is tracked and discussed, including WPU synthesis, flexible sensing principles, and conductive filler types. Finally, the unique multifunctionality of WPU-based flexible sensors and their wide range of applications are summarized, and the future development prospects of WPU-based flexible sensing materials are outlooked.