Recent Advances in Flexible Sensing Systems for Underwater Environments: Sensing, Protection, Adhesion, and Applications

Flexible sensing systems in underwater environments face formidable challenges in maintaining signal fidelity and structural integrity. This review systematically evaluates technical strategies for the synergistic integration of three core modules: mechanoelectrical transduction, encapsulation protection, and interfacial adhesion. We first analyze mainstream sensing mechanisms, including triboelectric, piezoelectric, resistive, capacitive, optical fiber, and magnetoresponsive approaches. We then summarize advances in waterproof and corrosion‐resistant encapsulation materials that support signal stability and device durability. Next, we discuss adhesive interfaces that achieve stable underwater coupling through chemical and physical adhesion mechanisms across diverse substrates and dynamic loading conditions. Finally, we review the representative underwater applications in motion monitoring, physiological sensing, human–machine interaction, and object grasping and outline future directions for wearable platforms that deliver higher precision, longer operational lifetime, and greater adaptability to varied underwater environments.