This project developed a water-tube-based TENG (WT-TENG) to convert ocean wave energy into electricity efficiently. Water is encapsulated in a tube of 6 cm long with a diameter of 1 to 2 cm. When waves hit and water moves in the tube between regions of the two electrodes, triboelectrification happens and electric currents can be generated.

Taking advantage of the flexibility of water, the WT-TENG can be operated in various modes. Moreover, WT-TENG addresses the problem of low electric charge density of conventional triboelectric nanogenerators (TENG) which is often based on solid/solid contact. Due to the high contact intimacy of water and the tube surface, the output volumetric charge density of the WT-TENG is significantly enhanced, reaching 9 mC/m3 at a frequency as low as 0.25 Hz, which is the highest recorded among all the existing TENGs for low-frequency energy harvesting.