Wire-shaped supercapacitor by hydrothermal self-assembly of graphene on copper wires
Author: G.Latessa, Delta Ti Consortium Project Manager
Energy harvesting refers to the set of processes by which useful energy is captured form waste or environmental sources and is converted into an usable form. These energy sources include almost all the possible forms such as solar/photovoltaic, thermal, vibration/mechanical, chemical and radiation/electromagnetic.
Some sort of Energy Harvesting has already been used for decades (just think of the bicycle dynamos), but nowadays the interest in this kind of solutions has exploded, spreading to more and more applications, in particular due to the widespread installation of wireless sensor networks that facilitated huge technology trends such as the Internet of Things (IoT) and Big Data (BD) collection and analytics.
These applications are characterized for low energy needs while the number of devices exploitable is huge. The miniaturized dimensions and the ability to modulate their composition in a well-controlled manner to create properties that are not possible in their bulk counterparts enable new nanostructured materials to enhance conversion efficiency lowering physical dimensions.
Despite the traditional bulk applications, recently discovered nanostructured materials allow thermoelectricity to be probably one of the most promising energy harvesting technology.
Starting from an overview of the novel trends on nanostructured materials used for energy harvesting, this talk is focused on the thermoelectric energy harvesting technology developed by Delta Ti Consortium, a public-private consortium established in 2011. The use of nanostructured polysilicon thin film as thermoelectric material, fully compatible with microelectronics production process, has allowed to overcome intrinsic weaknesses (material and process costs) of conventional thermoelectric devices, typically based on Bi2Te3 and metallurgic process.
