Designer Peptide-PVDF Composite Films for High-Performance Energy Harvesting

Polymers and peptides have recently been considered as promising materials for piezoelectric energy harvesting because of their biocompatibility and enormous design possibility. However, achieving significant output voltages while meeting environmental safety requirements, low cost, and easy fabrication remains a major challenge. Herein, lipidated pseudopeptide incorporated poly(vinylidene fluoride) (PVDF) composite films are fabricated. Adding lipidated pseudopeptide (BLHA) increases the electroactive phase content, reaching the maximum for the 2 wt% composite film. The composite film containing 2 wt% BLHA manifests the highest dielectric constant and remnant polarization (P_r ), among others. A piezoelectric energy harvesting device fabricated with this film generates open-circuit output voltages up to 23 V, five times amplified output compared to pure PVDF. To the best of our knowledge, this material is superior among the peptide-based piezoelectric energy harvesters reported in the literature. The device is flexible, durable, low cost, and sensitive to high and low pressures. It can power up multiple liquid crystal display panels when pressed with a finger. The non-covalent interaction between BLHA and PVDF is the reason behind the composites' improved piezoelectric response. Density functional theory calculations also support this notion.