Increasing the output charge quantity of triboelectric nanogenerators via frequency multiplication with a multigap-structured friction layer

The output current from a triboelectric nanogenerator (TENG) primarily depends on the amount of triboelectric charge existing on the friction layer. The triboelectric charge capacity and charge-driving ability of the friction layer are the key parameters for enhancing the output performance of a TENG. In this paper, we developed a new TENG with a multigap-structured friction layer. The presence of these gaps creates additional contacts between the friction layers, which can induce additional separated triboelectric charges and increased output charge quantity. Moreover, because of these gaps, the TENG generates more output current pulses for each driving cycle, which implies that the frequency of the output current can be several times the driving frequency. In one driving cycle, a generic TENG without any gaps in the friction layer generates 2 current pulses and a unit area charge quantity per cycle (UCQC) value of 0.23 nC cm(-2), while a TENG with seven gaps in the friction layer can generate around 14 current output pulses and UCQC value of 294 nC cm(-2), which is 1.18 times the value of the record one. This work can contribute toward a rapid increase in TENG performance, thereby accelerating its applications.