A novel versatile nanocomposite film with outstanding piezoelectric, ferroelectric, and dielectric properties

Abstract

The current global chip shortage and energy crisis has prompted research community to investigate alternative electronic and energy materials with improved performance. Here, we propose a versatile and easy to fabricate ceramic-free nanocomposite film, based on fluoropolymers and amine-functionalized graphene oxide (AGO) nanosheets with great application potentials in non-resonant energy harvesters, voltage-generating sensors, and ferroelectric random access memories. The electrical and electromechanical properties of pristine fluoropolymers are inferior due to their low polar crystalline phase content, leading to weak spontaneous and remanent polarization. By using intermolecular anchoring strategy as an interfacial coupling mechanism, we have achieved outstanding voltage coefficient, energy density, and energy-harvesting figure of merit values of 0.30 Vm/N, 4.75 J/cm3, and 14 pm3/J, respectively, making the work one of the best ceramic-free nanocomposites reported so far. Employing differential calorimetry, wide-angle and small-angle X-ray scattering analyses, we demonstrate that AGO incorporation leads to formation of bigger crystallites and higher β/α ratio, which translates into remarkably high remnant polarization of 11.3 µC/cm2. We believe this work can open up new insights towards structural and morphological tailoring of fluoropolymers to enhance their electrical and electromechanical performance and pave the way for their industrial deployment in next-generation wearable electronics and human-machine interfaces.

Inkjet-printed flexible piezoelectric sensor for self-powered biomedical monitoring

“…4.1-Ink Formulation and Printing: 600 mg PVDF-TrFE (70 mol% VDF and 30 mol% TrFE) powder (Sigma Aldrich, France) was dissolved in 100 ml DMF at 60 ºC for 1 h to form a 6 mg/ml solution. A 1.20 mg/ml AGO dispersion in DMF was synthesized according to the procedure described in our previous work [23]. 0.5 ml of AGO dispersion was added to the PVDF-TrFE solution and mixed thoroughly to form a 0.1 wt% AGO nanocomposite inkjet ink.…”

“…This work, presents fabrication of inkjet printed flexible piezoelectric sensor based on PVDF-TrFE and amine functionalized graphene oxide (AGO). The main reason for using AGO nanosheets is due to presence of primary amine and hydroxyl groups that offer strong hydrogen bonding with polymer chains, which results in dipole alignment, lamellae enlargement, and inducing polar β-phase formation as shown in our previous work [23]. The fabricated sensor was then used to monitor biomedical signals such as joint bending, finger taps, and swallowing.…”