Aspartame Peptide-Based Piezoelectric Supramolecular Material Toward Energy Harvesting

Peptide assemblies with non-centrosymmetric structures have been developed as piezoelectric supramolecular materials toward nanotechnology. However, the variety of peptide-based piezoelectric materials remains limited. Herein, for the first time, we have explored the piezoelectric properties of aspartame dipeptide-based supramolecular crystals toward energy harvesting. The crystal structure indicated that aspartame supramolecular materials form a non-centrosymmetric structure with hydrophilic channels extending along the b-axis, driven by intermolecular hydrogen bonds. Notably, density functional theory (DFT) calculation revealed a significant piezoelectric response of aspartame crystals with a maximum piezoelectric coefficient of 37.9 pC/N. Furthermore, the aspartame crystal-based piezoelectric device generated an output voltage of ∼0.62 V and a short-circuit current of ∼2.08 nA under a mechanical force of 50 N. This device maintains stable performance over 10,000 press-release cycles. This work investigates the piezoelectricity of aspartame-based crystals, expanding new avenues for the development of peptide-based piezoelectric supramolecular materials.