Experimental investigation on the electrical performance of a solid-liquid tubular triboelectric nanogenerator in pipeline system

To explore the electrical performance of solid-liquid triboelectric nanogenerators for monitoring the state of water pipe systems, a solid-liquid tubular triboelectric nanogenerator (SLT-TENG) was developed, using water as a direct frictional material. Experiments were conducted to investigate the effects of various factors on the electrical performance of the SLT-TENG, such as water flow conditions, ion concentration, temperature, electrode dimensions, and multi-unit operation. The results demonstrated that the nanogenerator produced an alternating current (AC) electric signal, generated by two types of frictional electrification: solid-liquid and solid-solid friction. The output signal of the SLT-TENG was highly sensitive to changes in the liquid flow conditions within the pipe system. The electric signal amplitude increased eight to nine times in the presence of sudden flow interruptions or large air bubbles. Additionally, the signal amplitude was found to increase with higher ion concentrations and larger electrode contact areas but decreased as temperature rose. Parallel operation of multiple nanogenerators further improved performance, leading to a 140.5% increase in signal amplitude and significant enhancement of other electrical parameters. These findings provide valuable insights for the application of SLT-TENGs in monitoring water pipe system conditions.