High Efficiency piezoelectric Alternative materials: Towards Environmentally-friendly solutions – HEcATE

Piezoelectric materials have the functionality of producing an electrical potential in response to an applied force or generating mechanical movement when subjected to an electric field. Nowadays, these materials are integrated in a wide range of devices such as fuel injectors, piezoelectric motors, printing heads and ultrasonic transducers (for NDT, underwater sonar systems or medical imaging). Since the discovery in the 50’s of lead zirconate titanate (PZT) piezoceramics, derived compositions have been developed to optimize their efficiency. Nowadays, PZT-based compositions are the dominant piezoceramics due to their high electromechanical properties and low cost. However, PZT materials contain lead (typically above 60 wt% in commercial products) and their increasing success is associated to health and environmental problems. From 2003 the European Union adopted the well-known waste electrical and electronic equipment directives (WEEE) and restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS). Therefore, tremendous efforts have been devoted to the development of competitive lead-free counterparts such as BaTiO3 or KNbO3 and their derivatives. In December 2012, the European Chemical Agency (ECHA) registered PZT in the candidate list of the REACH directive. Thereby the pressure increased again with the objective to replace as soon as possible lead-based materials by safer materials with at least equivalent performance.
In HEcATE project, a wide French consortium proposes to set up a research axis from the development and optimisation of high efficiency piezoelectric lead-free materials to the manufacturing of several demonstrators and prototypes for underwater and medical applications via an up scaling approach. This consortium is composed of seven partners with four public laboratories (François-Rabelais University – GREMAN, University of Limoges - SPCTS in close collaboration with a Ceramic Technology Transfer Center, Institut de Chimie de la Matière Condensée de Bordeaux and l’Institut d’Electronique, de Microélectronique et de Nanotechnologie), one private research corporate laboratory (Thales Research & Technology), one pilot platform (Cristal innov) and one SME (VERMON SA). The project aims at developing engineered lead-free materials including single crystals and textured ceramics to achieve high performance while maintaining low cost by industrial processes. The lead-free materials developed within the project will be assessed through relevant prototypes. Simulation tools will also be designed to support developments of engineered materials and new demonstrator designs. HEcATE project addresses relevant challenges of the call through its thematic: “Challenge 3.3: Stimuler le renouveau industriel, axis Products (conception, processing & materials)”, related to material properties and functionalities. The main objectives defined by the project partners are: (1) Scaling up of the process for isotropic ceramics based on an analysis of the performance safety and cost-benefit; (2) Exploring lead-free single crystal processing and identification of the suitable orientation of single crystals to achieve high performance; (3) Exploring domain engineering possibilities through ceramics texturing in order to reduce cost as compared to single crystals; (4) Exploring an innovative deposition method for low cost thick films; (5) Fabrication of prototypes for medical imaging and underwater applications in view of large scale production.
These objectives are of primary interest as we are now in a period where the transition to these new lead-free materials will be inescapable, so French industry must be prepared to commercialize these materials and end-users to integrate them in their devices. This is the condition to remain competitive but also be able to increase their markets in Europe and worldwide.