Self‐Powered Underwater Force Sensor Based on a T‐Shaped Triboelectric Nanogenerator for Simultaneous Detection of Normal and Tangential Forces

Abstract The force distribution in the oceans, which cover 71% of the Earth's surface, is relatively unknown compared to the cosmos between Earth and 13.8 billion light years away due to the lack of sensors that can operate over long periods in a harsh underwater environments. Herein, a self‐powered underwater force sensor (SUFS) is reported based on a T‐shaped triboelectric nanogenerator (T‐TENG) for simultaneous detection of normal and tangential forces of finger touching as well as water flow exerted on the underwater objects. The SUFS based on two coupled TENGs can detect normal and tangential forces working in different TENG modes. The T‐shaped structure and atmosphere of the airbag inside the SUFS are optimized for improved electrical outputs. Furthermore, simple method suitable for mass production is also proposed to achieve a superhydrophobic surface with an underwater anti‐interference function. The SUFS can effectively monitor the angle α, force, and frequency of the kayak paddle and finger touching, and is promising for self‐powered intelligent motion sensing, soft robotics, human–computer interaction, and ocean monitoring in general.