Research Projects

The proposed research aims to develop sustainable, biocompatible, and multifunctional peptide-based materials with tunable piezoelectric, ferroelectric, and optoelectronic properties. This effort addresses the critical need to replace conventional inorganic piezoelectric materials such as lead zirconate titanate (PZT), barium titanate, and zinc oxide. While these materials exhibit excellent electromechanical properties, they are hindered by toxicity, brittleness, non-biodegradability, and high-energy processing. These drawbacks limit their suitability for emerging technologies, including wearable electronics, implantable biomedical devices, and environmentally benign energy systems. In contrast, peptides provide a unique combination of biocompatibility, lightweight nature, synthetic tunability, and the ability to self-assemble under mild conditions, making them ideal candidates for next-generation soft functional materials. The project centers on short peptides incorporating D-proline, such as Boc-DPro-Gly-X-NHBn-OMe and Boc-DPro-Leu-X-NHBn-OMe, where X is any non-aromatic amino acid. These sequences adopt well-defined secondary structures, such as β-turns or β-sheets, depending on the X residue. Notably, they often crystallize in non-centrosymmetric space groups, crucial for expressing piezoelectricity, ferroelectricity, and second harmonic generation (SHG). Remarkably, even in the absence of aromatic residues, these peptides form non-centrosymmetric crystals, suggesting that π-π stacking is not essential for such functionalities. Instead, the assemblies are stabilized by backbone hydrogen bonding, chiral side-chain interactions, and hydrophobic packing. This insight opens a path toward minimalistic, synthetically accessible, and environmentally friendly piezoactive materials. The methodology integrates multiple experimental and computational techniques to decipher the structure–function relationships of these peptide systems. Gas-phase laser spectroscopy will reveal intrinsic conformational preferences free from solvent effects. FTIR and 2D-NMR spectroscopy in solution will probe the influence of solvents on secondary structure, while single-crystal X-ray diffraction will determine packing motifs and crystallographic symmetry in the solid state. Quantum chemical calculations will complement the experiments by correlating peptide folding and crystal packing with dipole alignment and net polarization. Preliminary findings strongly support the viability of this approach. Boc-DPro-Gly-Ala-NHBn-OMe adopts a double β-turn structure across gas, solution, and solid phases and crystallizes in the non-centrosymmetric P2₁ space group, indicative of piezoelectric and SHG potential. Similarly, Boc-DPro-Leu-NHBn-OMe forms a persistent single β-turn across phases and crystallizes in the non-centrosymmetric P1 space group. These results demonstrate that short DPro-containing peptide scaffolds can consistently form robust supramolecular structures with emergent electromechanical properties. This project is innovative in using non-aromatic peptide scaffolds to engineer functional materials. It departs from conventional strategies relying on aromatic stacking and instead utilizes hydrogen bonding, hydrophobic effects, and chirality to drive functional assembly. The multimodal, phase-spanning approach offers an unprecedented understanding of how molecular conformation and packing influence macroscopic properties. By systematically varying side-chain chemistry and environmental conditions, this work aims to establish a sequence-to-function framework for designing biodegradable, piezoelectric biomaterials. The proposed research aligns directly with the goals of the ANRF-ARG initiative by translating molecular-level understanding into real-world applications in flexible electronics, bio-integrated sensors, and soft energy-harvesting technologies.