چكيده به لاتين
Recently triboelectric nanogenerators (TENG) has been the center of attention by many research groups as an energy source for low power electronic devices. Simple fabrication, flexibility and biocompatibility are among especiall features of TENG. Surface charge accumulation on dielectric layer is essential to energy production in TENG. Therefore, modeling and study of temporal behavior of surface charges in TENG are of utmost importance. In this reaecrh, a new model of charge accumulation in TENG devices is presented. To develop this model, a novel definition is offered for the non-conformal metal-insulator-metal contacts. In this vision, roughness parameters of both contacting layers and the effective air gap are considered. Parameters of the model are measured using a new surface charge evaluation technique. Unlike current surface charge evaluation techniques, this methode employs a simple half-wave rectifier as test circuit in connection to TENG. Employing the proposed model, simulation of the TENG output is performed more accurately with 5 to 9 percent improvement. In this thesis, for the first time, it is shown that half-wave rectifier outperforms full-wave rectifier in delivering the maximum energy to a capacitive load with a factor of 4.92. To simulate the dynamic behavior of surface charges and to validate the model, a charge sensitive circuit is offered. The circuit, Bennet’s doubler, which shows unstable output behavior is selected to simulate time-dependent variation of surface charges. The results show that the capacitive load in the Bennet circuit is quickly charged to 800 V, whearas this value is below 200 V for half-wave and full-wave circuits. This circuit, as another novelty in this research, is also employed to determine the sign of stored charges on the surface of the dielectric layer of TENG devices. Finally, in this research, current lumped models for TENG are improved to incorporate the sign of surface charges.
