Designing Rules and Optimization of Triboelectric Nanogenerator Arrays

Abstract

A triboelectric nanogenerator (TENG) is an effective means for the conversion of mechanical energy into electricity. Although Maxwell's displacement current is the underline mechanism of TENGs, the spatial and temporal variations of the electric field and electric displacement remain elusive, which prohibits an effective optimization of the energy conversion process. Here, the electric field distribution and energy dynamics of TENGs is determined using 3D mathematical modeling. The electrical energies stored in TENGs and extracted into the external circuit are calculated quantitatively whereby the ratio of the two, defined as the output efficiency, is obtained. Then, the power density and energy density of TENGs are defined. Utilizing the principle of virtual work, the minimum required external force–time relationship is evaluated. The influence of device parameters, geometry, and optimum conditions are discussed systematically so as to determine general optimization guidelines for TENGs. In addition, although the fringing electric field is practically inevitable, adjustments of the gap distance between neighboring TENG devices to assure that an optimized fringing electric field is “leaked”, is demonstrated to lead to improvement in a TENG array. Then, for the first time, this work presents universal design rules and holistic optimization strategies for the network structure of TENGs.