Structuring BaTiO 3 /PDMS Nanocomposite via Dielectrophoresis for Fractional Flow Reserve Measurement
Résumé
This work focuses on the development of piezoelectric sensors for the fractional flow reserve (FFR) technique, a procedure based on the measurement of blood pressure within a vessel to evaluate the severity of coronary stenosis. Considering the medical application, biocompatibility is a mandatory requirement that justifies the selection of fillers and matrix. Two composites made of lead-free barium titanate nanoparticles (BaTiO3) incorporated in polydimethylsiloxane (PDMS) elastomer are developed: the first composite with particles randomly dispersed and the second one with particles aligned along one direction, via an innovative technique known as dielectrophoresis. The experimental characterization indicates that the electroactive and dielectric properties are coherent with the models’ prediction, confirming that the alignment of the filler gives rise to considerably enhanced dielectric and piezoelectric proprieties relative to the random dispersion. Thermal stability together with X-ray diffraction is conducted, demonstrating superior piezoelectric response of the structured sample under high-temperature conditions. FFR application is then simulated by applying an arterial pulse-shape stimulus on the developed sensor, which is finally integrated into a catheter and directly inserted in a simulation arm.