# Peptide Sequence Programmed Piezoelectric Response by Supramolecular Self‐Assembly

## TL;DR

Researchers designed peptide crystals that generate electricity from mechanical force, achieving high performance in nanogenerators.

## Contribution

A new method for creating piezoelectric crystals using tripeptides with phenylalanine at the center, achieving record performance in aqueous environments.

## Key findings

- Tripeptides with phenylalanine self-assemble into stable piezoelectric crystals with a coefficient of 24.0 pC N−1.
- Nanogenerators using these crystals produce an open-circuit voltage of 2.57 V under 50 N force.
- Asymmetric molecular packing is confirmed as the source of high piezoelectric performance.

## Abstract

Piezoelectricity has attracted significant attention for its ability to convert mechanical energy into electricity, especially when biological molecules are incorporated into materials. However, natural biomaterials are limited by low piezoelectric coefficients, necessitating synthetic alternatives. Short peptides offer advantages such as ease of synthesis, biocompatibility, and tunability, making them promising candidates. In this study, hydrophobic tripeptides are used to fabricate stable piezoelectric crystals. When phenylalanine occupies the central position, the tripeptides self‐assembled into uniform, thermally stable crystals. Piezoresponse force microscopy (PFM) reveals a high effective piezoelectric coefficient of 24.0 pC N−1, attributed to strong asymmetric molecular packing, confirmed by microcrystal electron diffraction (MicroED) and density functional theory (DFT) analysis. Nanogenerators based on these crystals achieve an open‐circuit voltage of 2.57 V under 50 N, the highest among short peptides in aqueous environments. These findings advance peptide crystal engineering and highlight their potential for high‐performance piezoelectric devices.

In this study, hydrophobic tripeptides are explored as building blocks for stable piezoelectric crystals. Tripeptides with phenylalanine at the central position self‐assembled into uniform, thermally stable crystals. Piezoresponse force microscopy reveals a high effective piezoelectric coefficient of 24.0 pC N−1, attributed to asymmetric molecular packing confirmed by MicroED and DFT analysis. Using these crystals in nanogenerators, an open‐circuit voltage of 2.57 V is achieved under 50 N force‐the highest reported for short peptides in aqueous environments. This work advances peptide crystal engineering and offers a promising route for high‐performance piezoelectric devices.