Optimizing solvent dipole moment enables PVDF to improve piezoelectric performance

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• The all-trans conformation (β-phase) is crucial for polyvinylidene fluoride (PVDF) piezoelectricity.
• Manufacturing high-performance PVDF piezoelectric sensors is challenging due to difficulties in inducing the all-trans conformation.

Purpose of the Study:

• To develop an effective and cost-efficient method for enhancing PVDF's piezoelectric properties.
• To investigate the impact of solvent polarity modulation on PVDF's β-phase formation and piezoelectric performance.

Main Methods:

• Utilized continuous vacuum technology to adjust the polarity of binary solvent mixtures (acetone and DMF).
• Investigated the interaction between the solvent's dipole moment and the PVDF β-phase dipole.
• Characterized PVDF films using Fourier transform infrared spectroscopy and piezoelectric constant tests.

Main Results:

• Achieved a pure PVDF film with high piezoelectricity (d33 ≈ -44.8 pC N⁻¹) and strong self-polarization at an acetone:DMF ratio of 4:6.
• The resulting A₄D₆ device demonstrated high sensitivity (S₁ = 0.182 V/N over 0.5 N–30 N) and driven capability (0.49 mW m⁻²).
• The device exhibited excellent reliability in electrical tests as a pressure sensor.

Conclusions:

• Optimizing solvent polarity via continuous vacuum technology is an effective strategy to enhance PVDF piezoelectricity.
• This approach offers a cost-effective route for producing high-performance piezoelectric sensing devices.
• The findings provide valuable insights for the development of advanced piezoelectric polymer applications.