Grafting-Induced Conformational Engineering Breaks Polarization Barriers in PVDF for High-Temperature Piezoelectrics

Polyvinylidene fluoride (PVDF) is valued for its chemical stability and ease of processing, but its natural formation of the nonpolar α-phase limits its ability to adopt the electroactive β- and γ-phases required for applications like sensors and energy harvesters. Existing methods to create these functional phases are expensive and inefficient or degrade material performance. To address this, we develop a scalable approach by chemically attaching poly(tert-butyl acrylate) (PtBA) chains to PVDF by using controlled polymerization (ATRP). This modification selectively adjusts the molecular conformation of main chains via interactions on side chains and main chains, lowering energy barriers during phase transitions from the α- to γ-phase and boosting the formation of the γ-phase during thermal processing. The optimized material shows a 16-fold increase in γ-phase nuclei compared to unmodified PVDF. The resulting films achieve a piezoelectric response (d33 = 85 pC/N) that is 7 times stronger than that of pure PVDF, retain high crystallinity, and reduce production costs compared to traditional methods. These insights enable precise control over PVDF’s structure, overcoming long-standing challenges in scaling up electroactive polymers. Our strategy bridges lab-scale innovation with industrial needs, advancing PVDF toward practical uses in flexible electronics, self-powered sensors, and energy-harvesting devices.