Quantitative characterization of the energy harvesting performance of soft-contact sphere triboelectric nanogenerator

Reliable and persistent power supply becomes a key issue for the embedded system and wireless condition monitoring system. The soft-contact spherical triboelectric nanogenerator (SS-TENG) is an effective way to harvesting the blue energy, which can enhance the maximum output charge by ten times compared with a hard PTFE equipped TENG. This paper summarizes the factors that affect the output performance of SS-TENG, such as fill rate, shore hardness, elastic modulus, bulk density and kinematic property of soft sphere. The elastic modulus and shore hardness of soft sphere are analyzed. A universal contact model is coupled with the configuration and basic principle of TENG, which can characterize the output of SS-TENG quantitatively. Furthermore, effects of sphere hardness, radius, excitation frequency and transfer charge are comprehensively analyzed. Theoretical results indicate that the optimized fill rate should be 0.83. These findings provide significant optimization approach for blue energy harvesting TENG.