Dr Fabrice Domingues Dos Santos, CEO Piezotech

Arkema

Keynote Speaker

Electroactive fluorinated polymers for printed electronics

Abstract :

Since the discovery of piezoelectric and pyroelectric properties of PVDF, fluoride-based polymers have attracted great research interest due to their potential applications in the fields of sensors, actuators, medical imaging, IR detectors, underwater acoustic transducers and the emerging organic electronics. The piezoelectric, pyroelectric, ferroelectric properties and transition behaviors were extensively investigated during the 70s and 80s. However, PVDF does not crystallize directly into a ferroelectric ß-phase. In order to obtain a ferroelectric material, PVDF thick films have to be mechanically stretched and poled under a high electric poling field. Such a complicated fabrication process has limited the development of PVDF-based electroactive devices. On the other hand, PVDF derivatives, such as the ferroelectric P(VDF-TrFE) copolymers directly form a ferroelectric crystalline structure from solution or melt. Thin copolymers ferroelectric films can then be easily processed via printing techniques and poled using a moderate voltage.

Recently, thanks to the richness of fluorinated polymer chemistry, a new class of polymers has been developed: the relaxor ferroelectric polymers. They are now commercially available. These printable terpolymers are based on vinylidene fluoride (VDF), trifluoroethylene fluoride (TrFE) and a third monomer [chlorofluoroethylene (CFE) or chlorotrifluoroethylene (CTFE)] which modifies the crystalline structure from normal to relaxor ferroelectrics. Compared to the normal ferroelectric polymers, these materials exhibit a very thin hysteresis curve, good mechanical properties, a high dielectric constant at ambient temperature and large deformations under an applied electric field.

We will present recent developments made using these materials in different fields, such as haptics, acoustics, sensors, OTFT dielectrics or energy harvesting.


Bio :

Fabrice Domingues Santos is born in 1970. He is graduated from Paris School of Physic & Chemistry (ESPCI). He got his PhD from Paris Pierre & Marie curie University in Polymer Physics. In 2000 he joined Arkema R&D. Since 2010 he is Piezotech CEO, an Arkema group company dedicated to the development of electroactive fluorinated polymers.