Tongtong Shen, Ke Li, Xin Zhao, Long Li, Feng Yang, Wenchi Han, Shaowei Lu, Hailan Kang, Donghan Li
In the era of deep integration between the Internet of Things and artificial intelligence, flexible sensors, as a critical bridge connecting the physical world with digital information systems, have shown remarkable potential in core areas such as health monitoring, human-computer interaction, and intelligent manufacturing. Currently, there is a focus on further enhancing the core performance metrics of flexible sensors-their conductivity, mechanical adaptability, and sensitivity-while expanding their sensing dimensions and diversifying their application scenarios. To achieve these goals, the design and construction of high-performance conductive networks by utilizing nanomaterials and liquid metal (LM) and the optimization and selection of substrate materials have become a central research focus in this field. This review summarizes the advances in the structural design, fabrication, sensing mechanism, and application research of polymer-based flexible sensors. It systematically introduces the construction of nanomaterials and LM conductive networks and their influence mechanisms on the performance of flexible sensors. Furthermore, it summarizes the synergistic performance optimization strategies based on nanomaterials, LM, and polymer matrices. Finally, it explores the diverse applications of polymer-based flexible sensors across various fields, offering insights into their development prospects.