A continuous piezoelectric film can include a plurality of fibers, each fiber including a polypeptide, wherein molecules of the polypeptide have electric dipole moments that are aligned such that the piezoelectric fiber provides a piezoelectric effect. The continuous piezoelectric film has at least one piezoelectric constant d31 or d33 that is at least 1 pC/N. The continuous piezoelectric film can be prepared hot pressing a mat of aligned piezoelectric fibers.