Piezoelectric sensor and instrument including such a sensor

An instrument, comprising:

• a piezoelectric sensor, including:
• a body with a central cavity;
• a membrane extending over the cavity;
• the membrane being attached to the body via its periphery and includes a carrier layer made of polymer and a sensitive layer) made of piezoelectric polymer material;
• and
• the membrane being capable of deforming or vibrating, wherein
• the sensitive layer is made of a material comprising a polymer filled with Al2O3 inorganic nanomaterials and not filled with organic nanomaterials;
• the polymer of the sensitive layer is selected from the group comprising polyvinylidene fluoride (PVDF), vinylidene fluoride and trifluoroethylene copolymer P(VDF-TrFE) and polyamide-11;
• the carrier layer is made of a material selected from the group including polyimide (PI) and polyether ether ketone (PEEK);
• a first aluminium conductive layer is interposed between the carrier layer and the sensitive layer;
• a second conductive layer is deposited on a portion of a free surface of the sensitive layer;
• and
• a transmission rod, a first end of which is intended to be applied against a mass that is capable of vibrating, and a second end of which bears against the membrane of the sensor.