Performance enhancement of polysiloxane-based nanocomposite TENGs through optimized MWCNT concentration

Introduction: This study 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). Methods: Flexible PS/MWCNT films were fabricated using the doctor blading method and characterized by Raman spectroscopy and scanning electron microscopy (SEM). Broadband dielectric spectroscopy was employed to analyze frequency-dependent permittivity, interfacial polarization, and dielectric loss. TENGs were assembled in a vertical contact-separation mode using nylon as the positive triboelectric layer and evaluated under controlled temperature and humidity. Statistical error analysis (n = 3) was applied to ensure quantitative reliability. Results: A co-optimal MWCNT concentration of 0.03-0.05 wt% enhanced dielectric permittivity and interfacial charge trapping, improving triboelectric output while keeping conductive losses low. Higher loadings led to nanotube aggregation and increased dielectric loss, degrading device performance. Discussion/Conclusion: The study establishes a quantitative correlation between dielectric spectroscopy and triboelectric output, providing mechanistic insight into performance enhancement and degradation. This framework offers practical guidelines for designing PS-based nanocomposite TENGs for wearable electronics, self-powered sensors, and portable energy-harvesting applications.