A capacitor that allows energy to be stored in a few nanometers for applications up to medium and high frequencies. The work published in Advanced Materials, the most prestigious journal in the sector
An innovative technology to produce robust, flexible and low-cost capacitors, capable of storing energy in a few nanometers and positionable on any type of substrate, even flexible.
The study by the team from the Department of Information Engineering of the University of Pisa coordinated by Giuseppe Barillaro was conducted in collaboration with Surflay Nanitec GmbH of Berlin and the Department of Physics of the University of Pisa, and was published in Advanced Materials (link), the most prestigious journal in the field of materials science.
“A capacitor - explains Giuseppe Barillaro - is able to store energy in an insulating material placed between two metal conductors. Its capacity increases as the thickness of the insulating material decreases.
The method we have developed allows us to control the assembly of capacitors called electrolytic, that is, those that typically use a liquid or gel with a high concentration of ions (called electrolyte) as an insulating material.
The electrolytic capacitors produced with our method have a thickness reduced by at least fifty times compared to current capacitors, while an operating frequency of at least fifty times higher.
Unlike current electrolytic capacitors, which work for low-frequency applications, such as power grids, the nano-capacitors from the University of Pisa can be used for medium and high-frequency applications, such as wireless communications".
The production process identified by the researchers is very simple: a metal substrate on which a surface charge has been induced is immersed in a liquid containing a nanometric-thick polyelectrolyte with the opposite charge, which then deposits on the metal. The substrate can then be immersed again in another liquid containing a polyelectrolyte with the opposite charge to the first, to form another layer. The process is very simple and can be automated with a machine that alternately immerses the metal in the two liquids, which also makes it extremely economical.
"The capacitor - concludes Barillaro - can be made on any type of substrate, even on curved and flexible materials, and on very large areas, paving the way for several possible applications in the field of wearable, automotive, and energy storage systems. For example, the intrinsic flexibility of polyelectrolytes would allow them to be used inside an electronic skin, as pressure sensors and/or to store energy, but the potential is endless, and in sectors that in the new industrial revolution of 5.0 will assume an increasingly marked relevance.
The work on innovative materials to store energy is in fact one of the research conducted in the FoReLab laboratory of the Department, dedicated to the development of technologies for industry and society 5.0.
