Self-assembled peptides, when aligned, hold great promise for power generation.
Nanogenerators capable of converting mechanical energy into electricity are usually made from metal oxides and lead-based perocytes. But these inorganic materials are not biochemical, so energy harvesting, electronic sensitization and the race to produce natural biochemical piezoelectric materials for the stimulating nerves and muscles continue.
Researchers from University College Dublin and the University of Texas at Dallas decided to explore peptide-based nanotubes, as they would be an attractive option for use within electronic devices and for energy harvesting applications.
In Journal of Applied PhysicsFrom the AIP publication, the group reports using a combination of ultraviolet and ozone exposure to generate a wettability difference and creates an applied field to create horizontally aligned polarizations of nanotubes on flexible substrates with interlocking electrodes.
“The piezoelectric properties of peptide-based materials make them particularly attractive for energy harvesting, because pressing or bending them produces an electric charge,” said Sausan Almohmad, lead author of the University of Dublin and a postdoctoral researcher.
There is also an increased demand for organic materials to replace inorganic materials, which are toxic and difficult to make.
“Peptide-based materials are organic, easy to make and have strong chemical and physical stability,” she said.
In the group approach, physical alignment of nanotubes is achieved by a pattern of an instability gap on the surface of a flexible substrate. This creates a chemical force that pushes the peptide nanotube solution from the hydrophobic region, which repels water, to the hydrophilic region with a higher contact angle, which attracts water, with a lower contact angle.
Not only did the researchers improve the alignment of the tubes, which is necessary for energy harvesting applications, but they also improved the conductivity of the tubes by creating composite structures Graphene Oxide.
“It is well known that when two materials with different work functions come into contact with each other, an electric charge flows from low to high work function,” Almoham said. “The main novelty of our work is that controlling the horizontal alignment of the nanotube by electric field and nanotube-assisted self-assembly has improved both current and voltage output, and further growth was achieved by incorporating graphene oxide . ”
The group’s work will be widely enabled within biological materials, particularly peptide-based ones, electronic devices, sensors, and energy harvesting applications, as two major limitations of peptide nanotubes – alignment and conductivity – have been improved.
“We are also exploring how charge transfer processes from bending and electric field applications can enhance Raman spectroscopy — the identification of molecules,” Almohan said. “We hope that both of these efforts can be combined to create self-activated biosensors with a wide range of applications, including biological and environmental monitoring, high-contrast imaging, and high-efficiency light-emitting diodes.”
References: “Peptide Nanotube-Energy Graphide Oxide Flexible Substrates with Electric Field and Wettability Assisted Self Assembly” by Senson Almohamed, Abi Thampi, Arva Bajaid, Fangga Zhang, Salvador Moreno, Kevin Cogh, Majid Minari-Jolandan, James H. Gaya “., Rice and Brian J. Rodriguez, 15 September 2020, Journal of Applied Physics.
DOI: 10.1063 / 5.0017899