Low-power electronic devices (autonomous sensors, micro-robots, mobile phones, medical sensors, industrial processes, housing, etc.) are expected to accompany us on a daily basis. The use of batteries is not always possible to power these devices. They have limited lifetimes and require an external intervention to be replaced. Given the low consumption of current electronic devices, it becomes today conceivable to operate these devices by recovering the energy available in the ambient environment (light, thermal, mechanical). The mechanical energy of ambient or biomechanical vibrations, typically hundreds of µW / cm3 to a few mW / cm3, would be sufficient to power current wireless sensor networks. Several demonstrators of mechanical energy harvesting by piezoelectricity have appeared in the recent years. In London, a discotheque operates piezoelectric (PZ) technology on its dance floor. In the USA, DARPA equips its soldiers with PZ generators to make them more autonomous. These applications are not yet at commercial stage, but IDTechEx analyzes predict that the market for energy harvesting using PZ devices is expected to start soon and to grow up to US $ 800 million in the next 10 years. This startup is difficult because until now most of the reported demonstrators are based on the use of small PZ crystals or thin films. Improvements in performance are achieved by the use of PZ ceramic fibers. These fibers are unfortunately fragile and cannot be integrated into flexible or large structures. There are currently no flexible, lightweight, mechanically resistant and efficient PZ materials as required for a viable mechanical energy harvesting.
The POETICS project will overcome this obstacle with a new generation of PZ fibers. These fibers will have a composite structure and will combine the flexibility of organic polymers with the high performance of inorganic PZ materials. They will allow easy manipulation and can be integrated into textiles, composites, and various structures of our environment. Unlike competing projects, we will use a fiber wet spinning technology. It will enable us to prepare fibers containing a high density of highly anisotropic PZ particles in order to maximize the interactions between the polymer matrix of the fibers and the inorganic inclusions.
This is a key point to achieve high coupling coefficients and high mechanical performances with fibers having a Young's modulus greater than 5 GPa and a tensile strength of at least 1 GPa. Moreover, given their unique structure of concentrated and oriented PZ nanoparticles, the fibers will be ideal objects to answer the very controversial fundamental questions concerning the confinement, finite size and surface effects on the ferroelectric and PZ properties of nanoparticles. To achieve the ambitious objectives of the POETICS project, we have gathered a multidisciplinary team of chemists (ICMCB) and physico-chemists (CRPP), who will cover research tasks from PZ particle synthesis to the demonstration of energy conversion through the manufacturing of fibers and the characterization of their properties. The new fibers will be produced from the laboratory scale to a pilot scale on a continuous multifilament spinning line with the contribution of a technological platform (CANOE) acting as a subcontractor. This extension will allow macroscopic characterizations and validation of the technology with the realization of an energy harvesting demonstrator.
Centre de Recherche Paul Pascal (Laboratoire public)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Centre de Recherche Paul Pascal
Institut de Chimie de la Matière Condensée de Bordeaux
Help of the ANR 509,622 euros
Beginning and duration of the scientific project: September 2017 - 48 Months