Silicon structures of the order of nanometers (nanostructures) can be integrated on chips and act as thermoelectric generators, directly converting heat into electrical energy.
The research comes from the team of electronic engineers of the Department of Information Engineering of the University of Pisa, who have published two works in international journals, demonstrating the validity of a technology based on a material, such as silicon, biocompatible and non-polluting (it is obtained from sand) for the production of "green energy".
"We have managed to produce a nanostructured silicon chip that produces electrical energy - explains Giovanni Pennelli, professor of electronics at the DII and coordinator of the research group - Typically, silicon chips consume energy to perform activities, such as doing calculations (microprocessors), transmitting information (cell phone chips), measuring quantities (temperature sensors, pressure, ...), and they need to be powered. Our device, on a chip like all the others, adds the missing piece: instead of consuming energy, it produces it by exploiting a hot surface (human body, radiator, other devices that heat up) and can power other devices without using batteries that are expensive, need to be recharged and also at the end of the production cycle must be recycled-reconditioned to avoid pollution.
“Our device - adds Elisabetta Dimaggio, electronics researcher at DII - works wherever there are electronics to be powered at low power, for example with sensor nodes, and could be a very important element to reduce costs and pollution in industrial contexts.
Furthermore, the thermoelectric device could also be used to cool surfaces, therefore not only as a generator but also integrated into systems that heat up during operation, such as huge data centers. The research was conducted in collaboration with IMB-CNM, CSIC of Barcelona, and appeared in the magazine “Small”.
For years, the DII research group has been studying the use of silicon for the production of electrical energy. In a research carried out in collaboration with the Universities of Warwick and Milano-Bicocca, published in the prestigious journal “Nano Energy”, the researchers have demonstrated that the efficiency of silicon in producing energy can be almost tripled compared to what was supposed so far.
“We have managed to demonstrate that silicon nanostructuring techniques - explains Antonella Masci, PhD student at DII and first author of the article in Nano Energy - allow not only to reduce thermal conductivity, with a notable benefit in thermal-electric conversion efficiency, but also to produce a lot of energy starting from waste heat.”
“Research that exploits the properties of some materials to produce green energy - comments Sergio Saponara, Director of the Department of Information Engineering - is essential to provide companies with the tools for a digital transition according to the principles required by the transformations of industry 5.0, which must have people and the environment at their center. The FoReLab laboratory of the Department, dedicated precisely to key technologies for 5.0, has among its most important lines of work that of the new generation of reconfigurable, adaptive and ecological ICT devices and systems that exploit innovative architectures and nanostructured materials to adapt their application and optimize their performance based on the conditions of use, industrial contexts and emerging applications”.
