Piezoelectricity

Electrical engineering

Physics

Piezoelectric coefficient

Volt

Fluoride

Engineering

Coupling (piping)

Dielectric

Ceramic

Voltage

Physical chemistry

Composite material

Inorganic chemistry

Chemistry

Materials science

Polarization (electrochemistry)

Ferroelectric polymers

Quantum mechanics

Electromechanical coupling coefficient

Optoelectronics

Polymer

Electric field

Ferroelectricity

Science

Electromechanical (EM) coupling-the conversion of energy between electric and mechanical forms-in ferroelectrics has been used for a broad range of applications. Ferroelectric polymers have weak EM coupling that severely limits their usefulness for applications. We introduced a small amount of fluorinated alkyne (FA) monomers (<2 mol %) in relaxor ferroelectric poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (PVDF-TrFE-CFE) terpolymer that markedly enhances the polarization change with strong EM coupling while suppressing other polarization changes that do not contribute to it. Under a low-dc bias field of 40 megavolts per meter, the relaxor tetrapolymer has an EM coupling factor (k33) of 88% and a piezoelectric coefficient (d33) >1000 picometers per volt. These values make this solution-processed polymer competitive with ceramic oxide piezoelectrics, with the potential for use in distinct applications.

Relaxor ferroelectric polymer exhibits ultrahigh electromechanical coupling at low electric field