Exploring the Ferroelectric Nematic Liquid Crystals for Electromechanical Performance Evaluation in PVDF-based Triboelectric Nanogenerators

The integration of ferroelectric nematic liquid crystals (FNLCs) into polymer matrices offers a promising route to enhance dielectric and ferroelectric properties of the composites and thus improve the surface charge generation, which can be exploited to explore the triboelectric energy harvesting application. In this study, we report the development of an advanced poly(vinylidene fluoride) (PVDF)-based composite self-supporting film by infusing a novel room-temperature FNLC (FNLC-1571) for high-performance triboelectric nanogenerators (TENGs). The composites were prepared via the spin coating method to achieve a uniform thickness (~100 μm) and controlled surface morphology. Incorporation of FNLCs within the PVDF matrix induced intermolecular nucleation, promoting enhanced crystallinity and preferential formation of the electroactive β-phase, as confirmed in related literature on LC-polymer composites. The presence of FNLC molecules, with their long-range polar order and high dielectric anisotropy, facilitates efficient dipole alignment and increases the net dielectric permittivity, thereby improving charge density during triboelectric contact. The fabricated films functioned as tribo-negative layers in a vertical contact–separation-mode TENG, paired with aluminum (Al) as the tribo-positive counterpart. The optimized device delivered an open-circuit voltage of ~60 V_PP and a short-circuit current (I_SC) of ~5 µA under low mechanical excitation (~10N force @ 15Hz), demonstrating high sensitivity to small-amplitude vibrations. The enhancement in triboelectric output is attributed to the synergistic effect of increased β-phase content, improved interfacial polarization, and optimized device geometry, which maximized effective contact area and charge transfer efficiency. This work establishes FNLC-infused PVDF composites as a viable and scalable material platform for next-generation self-powered sensors, portable electronics, and IoT-compatible energy harvesting systems.