Pressure measuring device

Abstract

Pressure Measurement Device This description relates to a pressure measurement device for a fluidic circuit comprising a substrate (10) covered by N piezoelectric sensors (11) arranged in a line on the same face of the substrate (10), where N is an integer greater than or equal to 2, each piezoelectric sensor (11) comprising at least one organic piezoelectric layer (103) disposed between a first electrode (101) and a second electrode (102). Figure for the abbreviation: Fig. 3

Description

Title of the invention: Pressure measuring device technical field

[0001] This description relates generally to devices for measuring pressure in a fluid, for example the devices can be used to measure blood pressure, pressure in hydraulic systems or pressure in air circuits. Previous technique

[0002] Pressure measuring devices for hydraulic systems can be used to detect leaks. These devices are stationary and allow pressure to be measured at fixed points. Each sensor provides a pressure reading at a given time t. Leaks are detected when there is a pressure difference between the fixed points.

[0003] In the case of surgery, the devices used allow the measurement of coronary flow reserve (FFR for "Fractional Flow Reserve"). This measurement provides access to a value at a single point.

[0004] Thus, the various measuring devices provide a value at a single point. They do not allow for obtaining pressure gradients localized in areas of interest. Summary of the invention

[0005] There is a need to have a device for measuring pressure and pressure gradients, in order to be able to identify any overpressures or underpressures due to pathologies or to detect any leaks, in a precise manner.

[0006] This goal is achieved by a pressure measurement device for a fluidic circuit comprising a substrate covered by N piezoelectric sensors arranged in line on the same face of the substrate with N an integer greater than or equal to 2, each piezoelectric sensor comprising at least one organic piezoelectric layer arranged between a first electrode and a second electrode.

[0007] Advantageously, N is between 2 and 10, preferably between 5 and 10.

[0008] Advantageously, the piezoelectric sensors comprise between 1 and 10 organic piezoelectric layers, preferably between 7 and 10 organic piezoelectric layers.

[0009] Advantageously, each piezoelectric sensor has a length between 5 mm and 10 cm, preferably between 1 and 4 cm, and a width between 1 mm and 2 cm, preferably between 1 mm and 1 cm.

[0010] Advantageously, each organic piezoelectric layer has a thickness of between 3 and 15 pm, preferably between 3 and 5 pm.

[0011] Advantageously, each organic piezoelectric layer is made of PVDF, or one of its copolymers, such as P(VDF-TrFE).

[0012] Advantageously, the first electrode and the second electrode are made of an electrically conductive polymer, preferably PEDOT-PSS.

[0013] Advantageously, piezoelectric sensors are covered by an encapsulation layer of a polymer material, for example, PDMS, PMMA, PVDF or one of its derivatives.

[0014] This goal is also achieved by a method of manufacturing a pressure measuring device comprising a substrate covered by N piezoelectric sensors arranged in line on the same face of the substrate with N an integer greater than or equal to 2, each piezoelectric sensor comprising at least one organic piezoelectric layer disposed between a first electrode and a second electrode, a vacuum annealing step being carried out to crystallize the piezoelectric layer.

[0015] This objective is also achieved by a method for measuring pressure in a fluidic circuit, the method comprising a step in which a pressure measuring device is introduced into the fluidic circuit, the measuring device comprising a substrate covered by N piezoelectric sensors arranged in a line on the same face of the substrate, with N an integer greater than or equal to 2, each piezoelectric sensor comprising at least one organic piezoelectric layer disposed between a first electrode and a second electrode, the pressure on the N piezoelectric sensors being measured independently, thereby determining whether the pressure is identical on the N piezoelectric sensors or whether the pressure differs between the N piezoelectric sensors. Brief description of the drawings

[0016] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0017] [Fig.1] represents, schematically and in three dimensions, a device according to a particular embodiment of the invention;

[0018] [Fig.2] represents, schematically and in cross-section, a device according to another particular embodiment of the invention;

[0019] [Fig.3] represents, schematically and in cross-section, a device according to another particular embodiment of the invention;

[0020] Fig. 4 represents, schematically and in top view, a device according to another particular embodiment of the invention;

[0021] [Fig.5] is a graph representing the polarization as a function of the applied field for a device having a PEN substrate and for a device having a PI substrate, according to different particular embodiments of the invention;

[0022] [Fig.6] is a graph representing the polarization as a function of the applied field for a device that has been annealed at 150°C for 15 min and for a device that has been subjected to vacuum annealing at 150°C for 15 min, according to different particular embodiments of the invention;

[0023] [Fig.7] is a graph representing the relative permittivity as a function of frequency for a device that has been annealed at 150°C for 15 min and for a device that has been subjected to vacuum annealing at 150°C for 15 min, according to different particular embodiments of the invention;

[0024] [Fig.8] is a graph representing the current as a function of voltage for devices having PEN and PI substrates, the devices having been subjected to vacuum annealing at 150°C for 15 min, according to different particular embodiments of the invention;

[0025] [Fig. 9] is a graph representing the relative permittivity as a function of frequency for devices having PEN and PI substrates, the devices having been subjected to vacuum annealing at 150°C for 15 min, according to various particular embodiments of the invention; and

[0026] [Fig. 10] is a graph representing resistance as a function of frequency for devices having PEN and PI substrates, the devices having been subjected to vacuum annealing at 150°C for 15 min, according to different particular embodiments of the invention. Description of the implementation methods

[0027] The same elements have been designated by the same reference numerals in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0028] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been represented and are detailed.

[0029] Unless otherwise specified, when referring to two elements connected together, this means directly connected without intermediate elements other than conductors, and when referring to two elements coupled together, this means that these two elements can be connected or linked through one or more other elements.

[0030] In the following description, when referring to absolute positional qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative, such as the terms "above", "below", "superior", "inferior", etc., or to orienting qualifiers, such as the terms "horizontal", "vertical", etc., it refers, unless otherwise specified, to the orientation of the figures.

[0031] Unless otherwise specified, the expressions "approximately", "roughly", and "in the order of" mean within 10%, preferably within 5%.

[0032] Subsequently, we will describe in more detail the devices for measuring blood pressure or the pressure in plumbing pipes or air conditioning circuits.

[0033] The device is interesting not only for measuring overpressure or underpressure in a fluid, but also for detecting the position of an anomaly.

[0034] The device is particularly interesting for vascular and cardiac surgery because the multiple sensors make it possible, in addition to knowing the blood pressure, to identify possible overpressures or depressions due to pathologies.

[0035] In surgery, measurement at several points simultaneously is particularly advantageous, unlike prior art devices which only allow measurement at a single point.

[0036] The device is also particularly useful for leak detection in hydraulic systems. Unlike prior art devices, which are stationary and measure pressure between separate points, the device allows for simultaneous measurement at multiple points. With prior art devices, leaks are detected between two fixed points, making it impossible to determine the exact source of a leak.

[0037] In the case of plumbing maintenance (for example for hydraulic circuits or air circuits), the device makes it possible to detect possible leaks even if invisible or inaccessible from the outside.

[0038] However, the device can also be used to measure pressure in any type of fluid.

[0039] We will now describe the device in more detail with reference to the attached figures.

[0040] As shown in Figures 1, 2 and 3, the pressure measurement device for a fluidic circuit comprises a substrate 10 covered by N piezoelectric sensors 11 arranged in a line on the same face of the substrate 10.

[0041] N is an integer greater than or equal to 2.

[0042] The device can include between 2 and 10 sensors 11 arranged in a line on the same face of the substrate 10, preferably between 5 and 10 sensors 11 arranged in a line on the same face of the substrate 10. By between X and Y, it is meant here and thereafter that the terminals are included.

[0043] Each sensor 11 comprising at least one organic piezoelectric layer 103 disposed between a first electrode 101 (also called lower electrode) and a second electrode 102 (also called upper electrode).

[0044] The device differs fundamentally from the prior art by the presence of several organic piezoelectric sensors 11 arranged in a line on the same face of the substrate 10.

[0045] When pressure is applied to a sensor 11, it is mechanically deformed, which generates an electrical signal. The sensors 11 can be deformed independently of each other, allowing for a detailed analysis of the pressure at several points in the fluidic circuit.

[0046] Thus, each of the sensors 11 provides information on the pressure. By processing the information from the different sensors 11, it is possible to determine whether there is overpressure or underpressure. It is also possible to determine the precise location of the anomaly.

[0047] The device comprising the sensors is elongated, preferably portable, and capable of measuring pressures and pressure gradients. This device allows access to any area of ​​the conduit.

[0048] The substrate 10 comprises a first main face 10a and a second main face 10b.

[0049] According to an advantageous embodiment, the sensors 11 are arranged only on one of the faces of the substrate, for example on the first face 10a ([Fig.3]).

[0050] According to another advantageous embodiment, the device comprises a first row of N sensors 11 arranged on the first face of the substrate 10a and a second row of N' sensors arranged on the second main face 10b of the substrate 10. Preferably, N is identical to N'.

[0051] Even more preferably, as shown in Figures 1 and 2, the sensors 11 of the first row are arranged opposite the sensors 11 of the second row (i.e. N = N').

[0052] The arrangement of sensors 11 on either side of the substrate 10 allows for a flat, undistorted substrate 10. Preferably, the sensors 11, arranged opposite each other, are identical.

[0053] Thus, the device can comprise PN portions of sensors 11, with N greater than or equal to 2. Preferably, each PN portion of sensors comprises a sensor 11 disposed on the first face 10a of the substrate 10 or each PN portion of sensors comprises a first sensor 11 disposed on the first face 10a of the substrate 10 and a second sensor 11 disposed on the second face 10b of the substrate 10.

[0054] Preferably, the sensors 11 comprise between 1 and 10 piezoelectric layers 103. When the sensor 11 comprises several piezoelectric layers 103, The sensor 11 is formed of a stack comprising an alternation of piezoelectric layers 103 and electrodes 101, 102. In other words, the stack is formed of a pattern 100 comprising a piezoelectric layer 103 arranged between two electrodes 101, 102. The stack begins and ends with an electrode.

[0055] Each sensor links a length L, for example, between 0.1 and 3 cm, preferably between 2 mm and 2 cm.

[0056] Each sensor linked, for example, a width 1 between 0.1 cm and 2 cm, preferably between 0.1 cm and 1 cm.

[0057] Each piezoelectric layer 103 has a thickness, for example, of between 3 and 15 pm, preferably between 3 and 5 pm. With such thicknesses, the detection of overpressures / underpressures is facilitated.

[0058] The distance L' between two sensors 11 is, for example, between 0.1 and 1 cm, preferably between 0.1 and 0.5 cm.

[0059] The different sensors 11 may have the same dimensions or different dimensions. Preferably, the dimensions are identical.

[0060] For example, as shown in [Fig. 2], the device comprises three sensor portions P1, P2, and P3. Each sensor portion comprises a sensor arranged on either side of the substrate 10. The first sensor portion P1 comprises sensors 11 having a single piezoelectric layer 103 (i.e., a single motif 100). The second sensor portion P2 comprises sensors 11 having four piezoelectric layers (i.e., four motifs 100). The third sensor portion P3 comprises sensors 11 having two sensor layers (i.e., two motifs 100). The dimensions (in particular, length and thickness) of the sensors 11 are different in each case.

[0061] The piezoelectric layers 103 are organic piezoelectric layers. Each piezoelectric layer 103 preferably comprises a polymer matrix of PVDF or a PVDF copolymer. This may be a copolymer of vinylidene fluoride and at least one other monomer copolymerizable with VDF. Advantageously, the copolymer comprises at least 50% by mol, preferably at least 70% by weight, and even more preferably at least 80% by mol of VDF, or even at least 90% by mol of VDF.

[0062] By way of illustration, the copolymerizable monomer(s) are, for example, chosen from chlorotrifluoroethylene (CTFE), chlorofluoroethylene (CFE), hexafluoropropylene (HFP), trifluoroethylene (VF3), methyl methacrylate (MMA), tetrafluoroethylene (TFE), and perfluoro(alkyl vinyl) ethers such as perfluoro(methyl vinyl) ether (PMVE).

[0063] For example, the copolymer is a copolymer of poly(vinylidene fluoride-trifluoroethylene) PVDF / TrFe, also noted P(VDF-TrFe) or PVDF-CTFE.

[0064] According to another embodiment, the polymer is not a ferroelectric polymer: it may be PVDF-HFP.

[0065] Each organic piezoelectric layer 103 can be a composite material. For example, layer 103 can comprise, in addition to the polymer matrix, ferroelectric particles.

[0066] For example, ferroelectric particles are in BaTiO3 (BTO), PZT (lead zirconate titanate), AIN, ZnO, or in SBN (Sr-Ba-Nb oxide) or SBT (Sr-Ba-Ti oxide).

[0067] Preferably, the electrodes 101, 102 are made of an electrically conductive polymer, preferably PEDOT-PSS (poly(3,4-ethylenedioxythiophene).

[0068] The electrodes 101, 102 have, for example, a thickness between 0.1 and 3 pm, preferably between 1.5 and 2.5 pm.

[0069] The materials forming the different sensors 11 may be identical or different. Preferably, they are identical. Even more preferably, each sensor 11 comprises electrodes 101, 102 made of PEDOT-PSS and a piezoelectric layer 103 made of P(VDF-TrFe).

[0070] The substrate 10 can be a flexible substrate, that is to say, it can deform reversibly.

[0071] The substrate 10 can be made of polyimide or PEN for example.

[0072] The thickness 10 of the substrate is, for example, between 25 pm and 125 pm.

[0073] The length of the substrate 10 will depend on the number of sensors. It is, for example between 0.5 and 20 cm, preferably between 0.5 cm and 10 cm.

[0074] The width 1' of the substrate 10 can be between 1 mm and 2 cm, preferably between 2 mm and 2 cm.

[0075] Preferably, the length / width ratio of the substrate is between 1 and 100 and even more preferably between 3 and 20.

[0076] The substrate 10 has an elongated shape and can be used in narrow conduits.

[0077] Electrical connection means are arranged to carry the signal from the sensors to the receiver.

[0078] Several solutions can be considered for conveying the electrical signal from the sensors to the receiver.

[0079] According to a first embodiment, the connection is made by means of electrical wires (i.e., electrically conductive wires). The wires are, for example, in an electrically insulating sheath. The wires may be braided or positioned concentrically.

[0080] According to another embodiment, the connection is made by means of electrical tracks (i.e., electrically conductive tracks). The tracks may be printed on substrate 10. The tracks can be arranged on one side of substrate 10 or on both sides of substrate 10.

[0081] The tracks can be made of a metal (gold or silver, for example) or of an electrically conductive polymer material. For example, the electrically conductive polymer material is PEDOT:PSS. It can also be a polymer in which electrically conductive particles are dispersed, for example, carbon particles.

[0082] Several configurations are possible, in order to connect the electrical tracks and / or electrical wires.

[0083] For example, it is possible to cover part of the lower electrode 101 with one of the electrical tracks.

[0084] The electrical tracks and / or electrical wires can be connected to the lower electrode 101 of a sensor by means of an electrically conductive adhesive (of the charged epoxy type for example) or by means of a weld.

[0085] Optionally, an electrically conductive plate (for example made of metal, in particular copper) can be positioned on the substrate 10, on the one hand, glued or welded to the lower electrode 101 and, on the other hand, glued or welded to the electrical wire or to the electrical track.

[0086] According to another embodiment, mechanical systems such as clips or rivets can be used to connect the sensor electrode to the wire or track.

[0087] The various connections can be covered by a hood. In particular, it is possible to use an electrically conductive hood. For example, the hood may contain nanoparticles. The hood makes it possible to seal any holes and / or prevent breakdown phenomena.

[0088] It is also possible to increase the stiffness of the substrate 10 by locally adding an additional layer to the substrate. For example, this could be a polymer layer. The polymer may be the same as or different from the polymer of the substrate. It could also be a metallized polymer layer. Polymer layers can be deposited by bonding. Alternatively, the additional layer is a dielectric layer, for example, one printed by screen printing. It could also be a metallic foil. The foil can have a thickness of between 10 and 1000 µm, preferably between 10 and 1000 µm. The foil can be made of zinc or aluminum.

[0089] The ground connection can be shared to reduce the number of electrical traces / wires. This reduces the footprint of the connections, and thus the size of the substrate. This is particularly advantageous for small-diameter fluidic circuits, typically in surgical applications.

[0090] The substrate 10 and the sensors 11 can be covered by an encapsulation layer. The encapsulation layer can be made of a polymer material, for example, polydimethylsiloxane (PDMS), poly(methyl methacrylate) (PMMA), polyvinylidene fluoride (PVDF) or one of its derivatives.

[0091] Encapsulation can be carried out by immersion, thermal evaporation or spraying of a solution. Advantageously, the encapsulation step is carried out after the electrical connections have been made.

[0092] Radio-opaque elements can be added to the device, for example, to the substrate 10 or to the encapsulation layer, between the sensor portions 11, in order to provide visual tracking of navigation within the target system. The elements are, for example, in the form of crosses, squares, or dots.

[0093] The pressure measuring device can be made according to the following steps:

[0094] a) deposit N electrically conductive zones on a substrate 10, the zones electrically conductive elements arranged in a line and intended to form the first electrodes 101,

[0095] b) form piezoelectric layers 103 on the electrically conductive areas,

[0096] c) form second electrodes 102 on the piezoelectric layers 103.

[0097] Thus, each piezoelectric sensor 11 comprises at least one organic piezoelectric layer 103 disposed between a first electrode 101 and a second electrode 102.

[0098] Steps a), b) and c) can be repeated to form a stack comprising several active layers. During the iteration, step a) is performed on the underlying piezoelectric layer 103.

[0099] The process further includes a vacuum annealing step carried out to crystallize the piezoelectric layer.

[0100] In step b), the piezoelectric material layer can be deposited by spin coating. Other types of localized deposition can be used, such as screen printing, spraying, or even inkjet deposition. Preferably, the piezoelectric layer is deposited by screen printing. In a single pass, the deposited thickness is between 1 and 20 µm. It is possible to superimpose several layers by screen printing until the desired final thickness is achieved.

[0101] The process also includes a step of crystallizing the layer into a piezoelectric material. This irradiation is, for example, carried out with a UV flash light, with a flash duration, or pulse, of between approximately 500 ps and 2 ms, a fluence (energy delivered per unit area) of between approximately 15 J / cm² and 25 J / cm², and with a light wavelength of between approximately 200 nm and 380 nm. The number of UV flashes, or pulses, produced during this Irradiation varies depending on the thickness over which the piezoelectric material is to be crystallized. For example, for a P(VDF-TrFe) thickness of approximately 2 pm, irradiation can be implemented with a fluence of approximately 17 J / cm², a pulse duration of approximately 2 ms, and a number of pulses of 5.

[0102] The piezoelectric material, possibly having undergone previous crystallization, is then subjected to annealing, for example, carried out at about 130°C for about 60 min, to finalize the total crystallization of the material.

[0103] The crystallization of the material can therefore be carried out in two stages: firstly, irradiation by UV light pulse to properly crystallize the second face of the layer in material in order to increase its thermal conductivity, then a thermal annealing completing the crystallization for the rest of the material not crystallized by the previous irradiation.

[0104] Alternatively, annealing can be carried out under vacuum. For example, it can be annealed at a temperature between 100 and 150°C. The pressure is, for example, 1 mbar. Vacuum annealing is, for example, carried out for a duration of between 1 and 3 minutes.

[0105] When the piezoelectric material is a P(VDF-TrFe)-based copolymer, a material polarization step is performed before use. This step can be carried out, for example, by applying a direct current voltage across its terminals via the electrodes. This polarization is performed only once for the entire lifetime of the material. This direct current polarization can be performed at room temperature or at high temperature (up to approximately 100°C). When the polarization is performed at room temperature, it is possible to apply a direct current voltage of up to approximately 150 V / m of layer thickness for a duration, for example, ranging from a few seconds to a few minutes. For example, a voltage of 120 V / m could be applied for 20 seconds.When polarization is performed hot, for example at a temperature of approximately 90°C, a DC voltage of approximately 50 V to 80 V per micron of layer thickness can be applied for a duration of approximately 1 to 5 minutes. The temperature is then lowered to ambient temperature, and the electric field applied to the material via the DC voltage is then switched off. Such polarizations allow PVDF to achieve a remanent polarization of between 6 pC / cm² and 9 pC / cm², for example, approximately 8 pC / cm².

[0106] The dipoles within the layer remain oriented in this way, even when the material is no longer subjected to this electric field. The material can thus be polarized by applying an initial bias voltage across the electrode terminals. Preferably, a material thickness of approximately 2 pm or less is chosen to promote the polarization of the material by this capacitance, and the voltage level electrical current applied between the electrodes to achieve the initial polarization of the material (when the material needs to be initially polarized).

[0107] Annealing is advantageously carried out at the end of the process, or between the different steps. Annealing is, for example, at a temperature between 100°C and 150°C, preferably around 100°C to remove residual traces of solvent and / or finalize the crystallization of the material.

[0108] At the end of the process, contact can advantageously be re-established.

[0109] The device is simple to use. It allows the pressure in a fluidic circuit (gas or liquid) to be measured. The measurement process comprises the following steps: - Introduce the pressure measuring device as described above into the fluidic circuit, - Measure the pressure on the N piezoelectric sensors 11, the pressure of each sensor 11 being measured independently, thereby determining whether the pressure is identical on the N piezoelectric sensors 11 or whether the pressure is different between the N piezoelectric sensors 11.

[0110] Various embodiments and variations have been described. A person skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to a person skilled in the art.

[0111] Finally, the practical implementation of the embodiments and variants described is within the reach of a person skilled in the art, based on the functional indications given above.

[0112] Illustrative and non-limiting examples of different embodiments

[0113] In these examples, the substrate with a surface area of ​​1 mm x 1 cm is locally covered by portions of sensors. The sensors comprise piezoelectric layers made of PVDF-TrFE. The electrodes are made of PEDOT:PSS.

[0114] The substrate is either poly(ethylene naphthalate) (PEN) or polyimide (PI). Initially, the piezoelectric layers are polarized ([Fig.5]).

[0115] The influence of annealing on polarization and permittivity was also investigated: one of the devices underwent simple annealing at 150°C for 15 minutes, and the other device underwent vacuum annealing (1 mbar) at 150°C for 15 minutes. The substrates were made of PI for these measurements (Figures 6 and 7). Vacuum annealing is preferred to simple annealing because it produces active layers with fewer grain boundaries and therefore less electrical leakage. The sensor performance is improved.

[0116] Figures 8, 9 and 10 show different properties (current as a function of applied voltage, permittivity as a function of frequency, resistance as a function of the frequency) of the devices depending on the nature of the substrate (PEN or PI). These devices were subjected to vacuum annealing at 150°C for 15 min.

Claims

Demands

1. Pressure measuring device for a fluidic circuit comprising a substrate (10) covered by N piezoelectric sensors (11) arranged in line on one face of the substrate (10) with N an integer greater than or equal to 2, each piezoelectric sensor (11) comprising several organic piezoelectric layers (103), each organic piezoelectric layer (103) being arranged between a first electrode (101) and a second electrode (102).

2. Pressure measuring device according to claim 1, characterized in that N is between 2 and 10, preferably between 5 and 10.

3. Pressure measuring device according to any one of the preceding claims, characterized in that the piezoelectric sensors (11) comprise between 7 and 10 organic piezoelectric layers (103).

4. Pressure measuring device according to any one of the preceding claims, characterized in that each piezoelectric sensor (11) has a length between 5 mm and 10 cm, preferably between 1 and 4 cm, and a width between 1 mm and 2 cm, preferably between 1 mm and 1 cm.

5. Pressure measuring device according to any one of the preceding claims, characterized in that each organic piezoelectric layer (103) has a thickness between 3 and 15 pm, preferably between 3 and 5 pm.

6. Pressure measuring device according to any one of the preceding claims, characterized in that each organic piezoelectric layer (103) is made of PVDF, or one of its copolymers, such as P(VDF-TrFE).

7. Pressure measuring device according to any one of the preceding claims, characterized in that the first electrode (101) and the second electrode (102) are made of an electrically conductive polymer, preferably PEDOT-PSS.

8. A pressure measuring device according to any one of the preceding claims, characterized in that the piezoelectric sensors (11) are covered by a layer encapsulation in a polymer material, for example, PDMS, PMMA, PVDF or one of its derivatives.

9. A method for manufacturing a pressure measuring device comprising a substrate (10) covered by N piezoelectric sensors (11) arranged in line on one face of the substrate (10) with N an integer greater than or equal to 2, each piezoelectric sensor (11) comprising several organic piezoelectric layers (103), each organic piezoelectric layer (103) being arranged between a first electrode (101) and a second electrode (102), The method being characterized in that a vacuum annealing step is carried out to crystallize the piezoelectric layer (103).

10. A method for measuring pressure in a fluidic circuit, the method comprising a step in which a pressure measuring device is introduced into the fluidic circuit, the measuring device comprising a substrate (10) covered by N piezoelectric sensors (11) arranged in line on one face of the substrate (10) with N an integer greater than or equal to 2, each piezoelectric sensor (11) comprising several organic piezoelectric layers (103), each organic piezoelectric layer (103) being disposed between a first electrode (101) and a second electrode (102), the pressure on the N piezoelectric sensors (11) being measured independently, thereby determining whether the pressure is identical on the N piezoelectric sensors (11) or whether the pressure is different between the N piezoelectric sensors (11).

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