Intrinsically elastic polymer ferroelectric by precise slight cross-linking

Abstract

Ferroelectrics are an integral component of the modern world and are of importance in electrics, electronics, and biomedicine. However, their usage in emerging wearable electronics is limited by inelastic deformation. We developed intrinsically elastic ferroelectrics by combining ferroelectric response and elastic resilience into one material by slight cross-linking of plastic ferroelectric polymers. The precise slight cross-linking can realize the complex balance between crystallinity and resilience. Thus, we obtained an elastic ferroelectric with a stable ferroelectric response under mechanical deformation up to 70% strain. This elastic ferroelectric exerts potentials in applications related to wearable electronics, such as elastic ferroelectric sensors, information storage, and energy transduction.

High-Curie-Temperature Elastic Polymer Ferroelectric by Carbene Cross-Linking

“…Ferroelectric Response of Cross-Linked P(VDF-TrFE-DB) under Strains. A fully elastic capacitor device using a sacrificial layer method with liquid metal (gallium, Ga) as the elastic electrode 14 was fabricated to assess the ferroelectric response of elastic polymer ferroelectrics under varying strains. The schematic structure of the elastic device is depicted in Figure 6A.…”

“…The process has been slightly modified according to our previous work. 14 Further details are provided in the Supporting Information.…”

“…In recent research endeavors, we have addressed this challenge by developing an intrinsically elastic polymer ferroelectric film. 14 This approach involves a precisely controlled "slight cross-linking" process, utilizing poly-(vinylidene fluoride-trifluoro ethylene) P(VDF-TrFE) 55/45 mol % as the base material and polyethylene glycol diamine (PEG-diamine) as the cross-linker. Remarkably, even under a substantial 70% strain, the film maintains a stable remnant polarization intensity (P r , ∼4.7 μC/cm 2 ), which underscores the promising potential of these materials for demanding applications.…”

“…Therefore, numerous efforts have been contributed to explore new ways, like “ferroelectric chemistry”, to prepare novel ferroelectrics. , Concurrently, the evolution of wearable electronics necessitates the transformation of functional materials, including conductors, , semiconductors, , and dielectrics, into stretchable or elastic forms to conform to biological tissues and accommodate substantial and frequent strains (up to 50 to 80% at 0.1–100 Hz) . Consequently, the fabrication of elastic ferroelectrics becomes an inevitable trend, holding immense potential for advancements in wearable electronics. − …”

Boosting Piezoelectricity via a Bimodal Pore Distribution: The Role of Small Pores

“…Consequently, polymorph manipulation is adopted to endow PVDF with a higher content of active β phase containing all-trans molecular chains, e.g., stretching, annealing, and field poling, for better piezoelectricity. Nevertheless, crystal deformation is characterized by a low ratio below ∼2% even if PVDF and its copolymers have neat β crystals, thus exhibiting limited improvement on the piezoelectric performance . Because the amorphous phase has a better deformation ability than the rigid crystals, the dimensional model is widely accepted to explain a high piezoelectricity that comes from variation on the dipole moment density ( P ) of bulk polymers by compressing the flexible amorphous parts. , Poisson’s ratio and thickness are nonneglectable factors for which enlarged deformation in the normal direction can guarantee huge dipole moment density gaps (Δ P ) and excellent piezoelectric performance, which can be enabled by the employment of a structural element as the ductile amorphous part.…”