Welcome to the FIESTA project website.
FIESTA (« Ferroelectric-ferroelectric transitions Induced by External STress for Applications in sensing and energy harvesting ») is a project funded by ANR (Agence Nationale de la Recherche), grant ANR-20-CE05-0026, under the axis "A Clean, Reliable and Efficient Energy". It includes LGEF INSA Lyon, FEMTO-ST, C2N and ELyTMaX as partners.
FIESTA aims at investigating stress-induced ferroelectric-ferroelectric phase transitions in ferroelectric/piezoelectric materials with two target applications developed throughout of the project: tunable acoustic filters with frequency hopping feature and small-scale energy harvesting devices for self-powered systems.
The project finds its motivations both in socio-economic challenges and associated scientific questions. Regarding the first aspect, the advent of new wireless devices (e.g., 5G or Internet of Things) has confirmed the issues of integration and energy supply. More precisely, reducing the number of filters required for frequency selection would drastically improve the integration while decreasing power consumption. Meanwhile, energy harvesting, aiming at providing viable and long-lasting energy supply when conventional batteries cannot satisfy such requirements (e.g., remote/confined or relatively harsh environments), has emerged with the spreading of distributed wireless sensor networks. Yet, output power of microgenerators may not always ensure reliable operation of energy source.
To address these challenges, FIESTA fosters transdisciplinary approaches and genuine scientific researches related to societal stakes. The project, including 3 scientific Work Packages and 2 technical ones, encompasses all the involved fields, from material (WP2) to application (WP1, WP5) through mechanical (WP3) and electrical (WP4) aspects, for the completion of its targets. The core of FIESTA is to turn what is usually considered as a limitation (phase transition in ferroelectrics) into advantages for obtaining telecommunication filters able to provide frequency hopping as well as ultra-efficient mechanical energy harvesting devices (a decade above state of the art). The objective is to investigate these stress-induced phase transitions in ferroelectrics and combine them with mechanical and electrical aspects to obtain globally optimized systems. Hence, interfaces between each field will be of prior importance leading to relevant scientific advances. Particularly, the combination of intrinsic material nonlinearities with induced ones from electrical interface through the mechanical structure, yielding multiscale nonlinearities, is an innovative aspect of FIESTA.
In addition to these global advances, FIESTA will also provide relevant scientific progresses in each of the research fields. On the material side, that provides a common ground to the other axes, the project aims at understanding the mechanisms related to stress-induced phase transitions and develop appropriate materials accordingly. The project will encompass ceramics and crystal films, more particularly using KTN due to their Curie temperature close to room temperature (facilitating phase transition) and polymers (PVDF and its derivative) that require lower stress. On the structural aspects, ways of converting strain inputs into significant stress will be developed, through inverse flextensor structure, or impacting device featuring frequency-up conversion. Taking advantage of the unique properties of the developed materials, electrical aspects will provide innovative auto-synchronous converters that allow virtuous energy cycles along with cold-start capabilities thanks to remnant polarization of the material after transition.
FIESTA consortium includes partners with internationally recognized expertise and significant experience in project management. They also show a strong, timely and cutting edge will for promoting transdisciplinary researches, with very good knowledge of interfaces between disciplines.
FIESTA outcomes encompass both genuine scientific aspects, through transdisciplinary innovative researches as well as cutting-edge advances in each of the involved respective fields, as well as a strong applicative will by targeting devices related to current challenges in energy field.
