Patterning piezoelectric thin film PVDF–TrFE based pressure sensor for catheter application

We report a thin PVDF–TrFE (polyvinyledenedifluoride–trifluoroethylene) copolymer film pressure sensor, fabricated using standard lithography process for cost-effective batch process, film uniformity, and high resolution of polymer patterning. PVDF–TrFE copolymer, a semi-crystalline material, was spin-coated into thin films (1 μm thick) to tap the near β-phase formation. Pressure measurements demonstrated that the thin film (1 μm) show better performance compared to thick film (6 μm) with no electrical poling or mechanical stretching. Thin film devices showed higher β phase formation from Raman spectroscopy measurements, which translate into high piezoelectricity for sensing. The sensors can operate over a broad pressure range of 0–300 mmHg, with fast recovery time of 0.17 s, suitable for real time flow measurements in catheter applications.