Electromechanical coupling modeling and analysis of contact-separation mode triboelectric nanogenerators

Abstract

Abstract An electromechanical coupling model (EMCM) is constructed, and a contact-separation mode triboelectric nanogenerator (CS-TENG) is analyzed. In consideration of the contact-impact force between the moving and fixed electrodes, a piecewise linear differential equation of the moving electrode is derived and combined with the equivalent circuit differential equation to establish the EMCM of a CS-TENG with nonlinear variation of electrode distance. By using the harmonic balance method and arc length continuation technique, the dynamic output characteristics of the CS-TENG are obtained, and the stability of the results is determined. Both numerical integration and dynamic tests are employed to verify the accuracy of the present EMCM. The necessity of considering the nonlinear variation of the electrode distance in the EMCM is fully demonstrated through comparisons with the results of the existing model. Based on these results, the effects of the vibration excitation amplitude, contact stiffness, and structural damping on the output characteristics of the system are discussed. The present EMCM and output characteristics analysis can serve as a reference for the structural optimization of CS-TENGs and further promote their practical engineering applications.