Performance Enhancement of Polysiloxane-based Nanocomposite TENGs through Optimized MWCNT Concentration

Abstract

This study systematically examines the effect of multi-walled carbon nanotube (MWCNT) loading on the dielectric behavior and triboelectric performance of polysiloxane (PS)-based nanocomposites for high-efficiency triboelectric nanogenerators (TENGs). Flexible PS/MWCNT films were fabricated using the doctor blading method and structurally characterized by Raman spectroscopy and scanning electron microscopy (SEM) to assess nanotube incorporation and interfacial interactions. Broadband dielectric spectroscopy (Immittance Meter E7-20) was employed to analyze frequency-dependent permittivity, interfacial (Maxwell–Wagner–Sillars) polarization, and dielectric loss as a function of MWCNT concentration. TENG devices were assembled in a vertical contact–separation mode using nylon as the positive triboelectric layer and evaluated under controlled temperature and humidity conditions with a Keithley DMM6500 multimeter. Statistical error analysis (n = 3), including uncertainty propagation to power and power density, was applied to ensure quantitative reliability. The results reveal a co-optimal MWCNT concentration range of 0.03– 0.05 wt%, where enhanced dielectric permittivity and interfacial charge trapping lead to a pronounced improvement in triboelectric output while conductive losses remain limited. At higher loadings, nanotube aggregation and near-percolation pathways increase dielectric loss and degrade device performance. The novelty of this work lies in establishing a quantitatively supported correlation between dielectric spectroscopy and triboelectric output, enabling a mechanistic interpretation of performance enhancement and degradation with filler loading. This integrated dielectric–triboelectric framework provides practical design guidelines for PS-based nanocomposite TENGs targeting wearable electronics, self-powered sensors, and portable energy-harvesting applications.