NU2023-005
INVENTORS Samuel Stupp* Yang Yang
SHORT DESCRIPTION Novel peptide material with precise nanoscale assembly, versatility in morphology, enhanced ferroelectric properties, high-temperature and electrochemical performance.
BACKGROUND Poly(vinylidene fluoride) (PVDF) is the leading organic ferroelectric material with multiaxial ferroelectricity, garnering significant attention due to its wide-ranging applications in electronics and electromechanical devices, but the ferroelectric phase is not thermodynamically stable. Achieving the desired electroactive polymorph for use in applications like actuators or sensors typically involves either mechanically drawing the polymer at low temperatures or introducing random copolymerization with additional monomers. However, these processes result in drawing-induced and copolymerization-induced chemical disorder, posing challenges in precisely controlling the nanoscale ferroelectric structure and subsequent properties.
ABSTRACT Researchers at Northwestern University utilized peptides to orchestrate the supramolecular assembly of oligomeric vinylidene fluoride (VDF) into ferroelectric and relaxor ferroelectric structures. This method capitalizes on the β-sheet secondary structure commonly found in proteins, guiding pure VDF oligomers to adopt the coveted conformation inherent in the ferroelectric polymorph of PVDF. This results in a thermodynamically stable ferroelectric VDF phase with the Curie transition temperature of 110 °C, higher than the commonly used VDF-based ferroelectric copolymers. Moreover, through adjustments to the peptide sequence resulting in weaker hydrogen bonding, researchers have uncovered the ability to induce "relaxor" phases that are characterized by weaker ferroelectricity but stronger electromechanical actuation. This biomolecular strategy holds the potential to yield sustainable and water-processable ferroelectric structures with tunable ferroelectric functionalities suitable for applications in sensing, memory, and energy transduction.
APPLICATIONS
ADVANTAGES
IP STATUS A US patent application has been filed.
PUBLICATIONS A manuscript detailing this technology is in preparation and will be submitted to a scientific peer-reviewed publication.
Liquid atomic force microscopy images of VDF supramolecular nanostructures with varying morphologies cast from 20 mM aqueous solutions after annealing. Corresponding height profiles were measured along the arrows.