All over the world, different kinds of fish are being consumed everyday. Due to the large consumption of fish, there is a large amount of fish biowaste produced. Because of this, a team in India at Jadavpur University in Koltata has been studying the recycling the fish by-products into energy harvester for self-powered electronics.
The researchers knew that the scales of fish contain collage fiber that has piezoelectric properties. This means that in application of a mechanical stress, electric charge can be generated. They have reported in Applied Physics Letters that they were able to harness the said property to create a bio-piezoelectric nanogenerator. To do this, they basically collected raw fish scales in the fish processing market. Then, they made them flexible and transparent with the use of demineralization process as explained by Dipankae Mandal, assistant professor of Organic Nano-Piezoelectric Device Laboratory at Jadavpur University.
According to Mandal, they were able to make a bio-piezoelectric nanogenerator, a.k.a. an energy harvester with the electrodes on both sides and then laminated it. The collagens contained by the processed fish scales serve as the active piezoelectric element. Despite the fact that it is already known that single collagen nanofiber possesses piezoelectricity, no study tried to focus on hierarchically organizing the collagen nanofibrils in the natural scales of the fish. To explore the self-alignment phenomena of the fish scale collagen, researchers used near-edge X-ray absorption fine-structure spectroscopy.
To clarify, the energy scavenging performance of the bio-piezoelectric was made possible through experimental and theoretical tests. These tests are capable of scavenging different types of the ambient mechanical energies including machine, movements of the body, sound vibrations and wind flow. Even using the finger to touch the bio-piezoelectric nanogenerator repeatedly can generate electricity to light more than 50 blue LEDs.
The researchers expect that their work can impact the field of the self-powered flexible electronics. Their discovery has the potential to be used in biocompatible and biodegradable electronics, edible electronics, e-health monitoring, and self-powered implantable medical devices. Also it can be used in both vitro and vivo diagnostics.
The end goal of the researchers is to design and engineer sophisticated ingestible electronics composed of nontoxic materials which will be useful for a wide range of therapeutic and diagnostic applications.