This study compares the force sensing properties of polyvinylidenefluoride (PVDF) and ElectroMechanical Film (EMFi) sensor materials. The PVDF material has solid structure whereas the structure of the EMFi material is cellular. Due to the structural differences, some of the material properties differ. The sensor operation is evaluated here with force sensitivity measurements. The sensitivity is measured in directions related to the length, width and thickness of the sensor. The EMFi material is sensitive to dynamic forces exerted normal to its surface, and the sensitivity in that direction ((58.7 ± 16.5) mV/N) was found to be about five-fold when compared to the corresponding value of the PVDF material ((12.6 ± 0.8) mV/N). The PVDF material also detects the forces related to its length and width while the EMFi material has very low sensitivity to these force components.
Rajala, S., & Lekkala, J. (2010). PVDF and EMFi sensor materials - A comparative study. In Procedia Engineering (Vol. 5, pp. 862–865). Elsevier Ltd. https://doi.org/10.1016/j.proeng.2010.09.245