A general charge compensation strategy for calibrating the voltage of a triboelectric nanogenerator measured by a capacitive circuit

The voltage is a key parameter of a triboelectric nanogenerator (TENG). However, when the voltage is measured by the voltmeters with a capacitive measurement circuit, there is a charge transfer between the TENG and the inner capacitor, making the measured voltage lower than its actual value. In this paper, a general charge compensation strategy is proposed for calibrating the measured voltage of a TENG based on the analysis of the capacitive measurement circuit. Two methods, the fixed capacitance derivation (FCD) and the variable capacitance fitting (VCF), are developed to calibrate the open-circuit voltage (Voc) of TENGs, and the calibration formulas of Voc are given, respectively. Firstly, a sliding freestanding triboelectric-layer mode TENG is taken as an example and the two methods are used to calibrate actual Voc. The results are consistent with that measured by the ammeter with non-capacitive measurement circuit, verifying the validity of the charge compensation strategy. For the other three basic working modes TENGs, the measured Voc are calibrated by the FCD method, which illustrate the universality of the charge compensation strategy. Finally, the relationship between the output voltage of a TENG and the load impedance is calibrated through the equivalent impedance including the inner capacitance of the voltmeter. The proposed charge compensation strategy for calibrating the voltage of a TENG measured by a capacitive circuit is of great theoretical and application significance for the establishment of a comprehensive evaluation system for TENG's output performance.

Automated summary

This paper introduces a charge compensation strategy for calibrating the measured voltage of a TENG, proposing two calibration methods based on capacitive measurement circuit analysis. The effectiveness and universality of the strategy are demonstrated through experiments, providing great theoretical and practical significance for the evaluation of TENG output performance.