Epitaxial growth of vertically aligned piezoelectric diphenylalanine peptide microrods with uniform polarization

Abstract Energy harvesting with piezoelectric nanomaterials spurred the development of self-powered nanosystems, and piezoelectric biomaterials are expected to play an important role in the biomedical field. Bio-inspired piezoelectric diphenylalanine (FF) peptide microstructures were fabricated on various substrates through a novel epitaxial growth approach. The low-temperature process produced vertically aligned FF peptide microrods with hexagonally arranged nanochannels and uniform polarization. Direct measurement of the piezoelectricity was achieved for the first time from a solid FF peptide single crystal and yielded an effective piezoelectric coefficient d 33 at 9.9 pm/V. The dense and aligned FF peptide microrods are advantageous for energy and sensing applications.