High Flexible, Ultra‐Robust Piezoelectric Nanogenerator Based on Hexagonal α‐Beryllium Oxide/PVDF Composite Thin Film: E‐Skin and Energy Harvesting Applications

Abstract Flexible piezoelectric thin‐film devices are gaining prominence in modern electronics due to their potential in intelligent and self‐powered applications. The performance of such devices strongly depends on the dielectric properties of the active layer materials. In this work, hexagonal α‐beryllium oxide (BeO) crystals are synthesized via a low‐temperature sol–gel polymerization process, with citric acid (CA) as a precursor at varying concentrations (1–4 wt%). Among these, BeO‐B ₈ (2 wt% CA) exhibited the highest dielectric constant (11.4). Further, a flexible piezoelectric nanogenerator (PENG) is successfully fabricated by combining polyvinylidene fluoride (PVDF) with various BeO‐X formulations (X = A ₈ , B ₈ , C ₈ , and D ₈ ). The BeO‐B ₈ /PVDF film combination exhibits the highest dielectric constant (24.87), indicating its potential for superior performance. A flexible piezoelectric nanogenerator (PENG) optimized with 0.5 wt% BeO‐B ₈ can generate 8 V and 2.5 µA under periodic mechanical stimuli, yielding a power density of ≈7.5 µW/cm ² at 20 MΩ load resistance. The proposed composite material properties are characterized through techniques including XRD, SEM, AFM, FTIR, dielectric, mechanical, and electrical analyses. The fabricated BeO‐B ₈ /PVDF PENG achieves potential results for self‐powered applications, including artificial e‐skin for spatial pressure sensing, jaw and finger movement tracking, and biomechanical and acoustic energy harvesting, underscoring its versatility in next‐generation electronics.