Peptide Sequence Programmed Piezoelectric Response by Supramolecular Self-Assembly.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Nanotechnology

Background:

• Piezoelectricity enables mechanical energy to electrical energy conversion, crucial for advanced devices.
• Natural biomaterials possess limited piezoelectric properties, driving the need for synthetic alternatives.
• Short peptides offer tunable, biocompatible, and easily synthesized options for piezoelectric materials.

Purpose of the Study:

• To engineer stable piezoelectric crystals using hydrophobic tripeptides.
• To investigate the piezoelectric properties and molecular packing of peptide-based crystals.
• To demonstrate the potential of peptide crystals in high-performance nanogenerators.

Main Methods:

• Fabrication of hydrophobic tripeptide crystals with phenylalanine at the central position.
• Characterization using Piezoresponse Force Microscopy (PFM) to measure piezoelectric coefficients.
• Structural analysis via microcrystal electron diffraction (MicroED) and density functional theory (DFT).

Main Results:

• Self-assembled, uniform, and thermally stable tripeptide crystals were successfully fabricated.
• A high effective piezoelectric coefficient of 24.0 pC N^-1 was achieved, attributed to asymmetric molecular packing.
• Peptide crystal-based nanogenerators demonstrated a record open-circuit voltage of 2.57 V in aqueous environments.

Conclusions:

• Hydrophobic tripeptides can be engineered into high-performance piezoelectric materials.
• Asymmetric molecular packing in peptide crystals is key to enhanced piezoelectricity.
• These findings pave the way for advanced, peptide-based piezoelectric devices and energy harvesting applications.