Correlation Between Structural Parameters and Piezoelectric Performance of PVDF Heart Sound Sensors

Area of Science:

• Biomedical Engineering
• Materials Science
• Sensor Technology

Background:

• Polyvinylidene fluoride (PVDF) offers excellent flexibility, piezoelectricity, and biocompatibility for flexible heart sound sensors.
• Optimizing PVDF sensor design is crucial for enhancing piezoelectric output performance.

Purpose of the Study:

• Systematically investigate the influence of sensor design parameters (area, aspect ratio, thickness, encapsulation) on PVDF sensor piezoelectric output.
• Establish governing relationships for optimizing PVDF heart sound sensor design.

Main Methods:

• Developed a parametric COMSOL Multiphysics model based on PVDF's direct piezoelectric mechanism.
• Fabricated and experimentally benchmarked sensor samples against simulations using custom test systems.
• Assessed heart sound acquisition fidelity using a dedicated simulation setup.

Main Results:

• Confirmed the direct piezoelectric mechanism through simulation and experiment.
• Measured sensitivities from 10^-15 to 10^-14 C/Pa with R² > 0.978.
• Observed increased output with larger sensor area and enhanced performance with PDMS encapsulation.

Conclusions:

• Validated a framework for optimizing PVDF heart sound sensors.
• Augmenting area, minimizing thickness, moderate aspect ratio, and PDMS encapsulation enhance performance.
• The validated simulation-experiment framework guides direct engineering of sensor design.