Molecular engineering of piezoelectricity in collagen-mimicking peptide assemblies

Abstract

Realization of a self-assembled, nontoxic and eco-friendly piezoelectric device with high-performance, sensitivity and reliability is highly desirable to complement conventional inorganic and polymer based materials. Hierarchically organized natural materials such as collagen have long been posited to exhibit electromechanical properties that could potentially be amplified via molecular engineering to produce technologically relevant piezoelectricity. Here, by using a simple, minimalistic, building block of collagen, we fabricate a peptide-based piezoelectric generator utilising a radically different helical arrangement of Phe-Phe-derived peptide, Pro-Phe-Phe and Hyp-Phe-Phe, based only on proteinogenic amino acids. The simple addition of a hydroxyl group increases the expected piezoelectric response by an order of magnitude (d35 = 27 pm V−1). The value is highest predicted to date in short natural peptides. We demonstrate tripeptide-based power generator that produces stable max current >50 nA and potential >1.2 V. Our results provide a promising device demonstration of computationally-guided molecular engineering of piezoelectricity in peptide nanotechnology.

Recent Advances in Organic and Organic–Inorganic Hybrid Materials for Piezoelectric Mechanical Energy Harvesting

“…More recently, the same group demonstrated the molecular engineering of piezoelectricity in collagen‐mimicking peptide assemblies. [ 93 ] The peptide‐based piezoelectric generator was developed using simple FF‐derived peptides N‐terminated by proline (Pro) or hydroxyproline (Hyp) moieties, namely Pro‐Phe‐Phe (P‐F‐F) and Hyp‐Phe‐Phe (Hyp‐F‐F). Figure shows the molecular structure, calculated theoretical piezoelectric coefficient, and piezoelectric energy harvesting generator of Pro‐Phe‐Phe and Hyp‐Phe‐Phe assemblies.…”

“…[ 149–153 ] Additional challenges in this area would be the biocompatibility and biodegradability of the molecular energy harvesters. In this regard, the existing limited reports [ 56,82,83,85,88–93 ] pertaining to amino acids and peptides are of great interest, but, more work is needed in terms of device performance, identifying the strong piezo‐ and ferroelectric materials, controlling the polarization directions and analyzing the accurate mechanism of piezo‐ and ferroelectric properties of these biomaterials. While piezoelectric energy harvesting devices based on Pb(II), Sn(IV), and Cd(II) typically show the best device performance, these metals are toxic. In general, lead‐based organic‐inorganic piezoelectric energy harvesters have been explored due to their excellent electromechanical properties.…”

“…These self-assembled tripeptide structures Reproduced with permission. [93] Copyright 2021 Springer Nature.…”

“…Additional challenges in this area would be the biocompatibility and biodegradability of the molecular energy harvesters. In this regard, the existing limited reports [56,82,83,85,[88][89][90][91][92][93] pertaining to amino acids and peptides are of great interest, but, more work is needed in terms of device performance, identifying the strong piezo-and ferroelectric materials, controlling the polarization directions and analyzing the accurate mechanism of piezo-and ferroelectric properties of these biomaterials. 8.…”

Ab-Initio Predictions of the Energy Harvesting Performance of L-Arginine and L-Valine Single Crystals

“…Initially the methodology was benchmarked with respect to three well-known inorganic piezoelectric materials; namely aluminium nitride (AlN), zinc oxide (ZnO) and α-quartz (SiO 2 ). This was then extended to the proteinogenic amino acids (Guerin et al, 2018a), biominerals (Guerin et al, 2018b), co-crystals (Ji et al, 2020) and peptides (Bera et al, 2021), with deviations from experiment ranging from 1-20%, which is highly accurate for identifying highperformance materials. The upper limit is observed in highly flexible materials with individual stiffness constants of less than 5 GPa.…”