PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮PVDF∮∮∮∮