Device, system, and method for interferometrically measuring the contraction of a contractile cell

Abstract

Device (1) for interferometrically measuring the contraction of at least one contractile cell (C), comprising a transparent substrate (2) having a lower face (21) and an upper face (22) coated with a partially reflective film (23); a flexible membrane (3), superimposed on the substrate (2), having a lower surface (31) and an upper surface (32). The upper surface (32) comprises a zone (34) suitable for culturing at least one contractile cell (C), and the lower surface (31) comprises at least one reflective element (33), placed at a respective at least one zone (34). The device (1) further comprises an optical cavity (4) defined between the lower surface of the flexible membrane (3) and said reflective film (23) of the substrate (2).

Description

[0001] TITLE: “Device, system, and method for interferometrically measuring the contraction of a contractile cell”

[0002] The following specification is provided for illustrative purposes and is not part of the present invention: “The project from which the present Patent Application originates has received funding from the European Union s ’ Horizon 2020 research and innovation programme under the TOX-Free Grant Agreement 964518. ”

[0003] DESCRIPTION

[0004] FIELD OF APPLICATION

[0005] The object of the present invention is usefully employed in the field of the evaluation of the behaviour of contractile cells, such as, for example, cardiac cells, i.e. cardiomyocytes. In particular, the present invention is employed to monitor and quantify cell properties, such as the contraction force of contractile cells.

[0006] Background art

[0007] Several devices adapted to monitor and quantify the cell contraction force are known in the background art.

[0008] In the prior art, three groups of devices may be identified, which are respectively based on pressure sensors, such as strain gauges or piezoresistive sensors, image tracking sensors or thin-film sensors. The latter are the most promising for evaluating the contractile force in terms of poor invasiveness, productivity, and ease of production. In use, thin-film sensor devices comprise a polymer flexible membrane, on which a layer of cardiac cells is cultured. The contraction of cells, such as of cardiac cells, causes a movement of the flexible membrane detectable by means of different measuring techniques. The latter quantify the movement of the membrane in relation to capacitive, resistive or, alternatively, optical parameters. Then, the conversion of the movement detected in the corresponding contraction force is carried out by means of direct or indirect measurements.

[0009] The reference standard for monitoring the contractile force of cells is the atomic force microscopy or the traction force microscopy.

[0010] It is known to make a “heart-on-chip” platform for measuring the contractile characteristics of cardiomyocytes based on the use of a cantilever, manufactured by a standard micro-electromechanical process. A micro-electrode array is embedded in the upper surface of the cantilever. Furthermore, the contraction measurement is based on the deflection of the cantilever detected by a laser vibrometer.

[0011] WO 2015 / 179947 Al describes a device and a related method for evaluating cell contraction, wherein the contractile cells are placed on a silicone film. Cell contraction causes a plurality of folds to form on the silicone film.

[0012] Further, WO 2015 / 150589 Al describes a device adapted to screen drugs on cells. This device comprises a stiff substrate having a surface, a light source for illuminating cells on the substrate surface, and a sensor configured to detect an optical signal from the illumination of the cells. This document teaches to evaluate the cell contraction force through optical detection, which allows the cell movement to be monitored. Prior art problems

[0013] In known devices, the evaluation of cell contraction occurs exclusively in bulk, i.e. considering the behaviour of the entire culture, without the possibility of monitoring a single contractile cell in isolation.

[0014] In the “heart-on-chip” platform, the presence of the laser vibrometer makes the contractile force evaluation complicated, since alignments and periodic calibrations of the instrument are required. In addition, this platform measures the movement from a single point, limiting the spatial resolution and scalability of the device. Finally, the stiffness of the polymer cantilever can significantly change in relation to the manufacturing process and, consequently, invalidate the measurement.

[0015] The device described in WO 2015 / 179947 Al has several drawbacks, such as, for example, the presence of a continuous film on which cells are cultured. The continuity of the film causes folds to form even on portions thereof that are not perfectly underlying the position of the cells below the contracting cell, thus generating crosstalk phenomena.

[0016] In the device of WO 2015 / 150589 Al, being the substrate stiff, it is impossible to calculate the cell contraction force solely from the cell movement.

[0017] Object of The Invention

[0018] In this context, it is an object of the present invention to provide a device, a system, and a relating method for interferometrically measuring a contractile cell which is capable of solving the aforementioned prior art problems. In particular, it is an object of the invention to obtain a device capable of obtaining high-sensitivity interferometric measurements, thus allowing to carry out an evaluation even on a single contractile cell.

[0019] It is a further object of the present invention to make available a device, a system and a relating method for interferometrically measuring a contractile cell alternative to the prior art.

[0020] Further objects are substantially achieved by a device, a system and a relating method for interferometrically measuring a contractile cell according to one or more of the appended claims.

[0021] SUMMARY OF THE INVENTION

[0022] The present invention relates to a device for interferometrically measuring the contraction of at least one contractile cell based on the concept of optical cavity. In particular, the device comprises a transparent substrate having a lower face and an opposite upper face coated with a reflective film. The device also comprises one or more flexible membranes, superimposed and spaced apart with respect to the substrate. Said membrane has a lower surface and an opposite upper surface, wherein the upper surface comprises at least one zone suitable for culturing at least one contractile cell, and the lower surface comprises at least one reflective element placed at a respective at least one zone of the upper surface. Further, the device comprises an optical cavity defined between the lower surface of the flexible membrane and said reflective film of the substrate.

[0023] Advantages of the invention By virtue of a specific embodiment, the present invention makes available a device comprising a plurality of reflective elements, each in a position corresponding to a contractile cell. Advantageously, it is possible to form arrays of sensitive elements within the device itself. Said arrays may be used as high-density sensors to determine the contractile force of a single contractile cell within a cell culture.

[0024] In other words, it is possible to independently evaluate the changes in the contraction force of different cells within different cultures.

[0025] Still by virtue of an embodiment of the present invention, it is possible to obtain a device for interferometrically measuring a contractile cell having at least one specific culture zone for one or more cells, and at least one respective reflective element at this zone.

[0026] This advantageously allows a highly sensitive determination of cell properties, since the plurality of reflective elements has an alternating and non-continuous pattern. The crosstalk phenomenon of the prior art is thereby limited.

[0027] Still advantageously, by illuminating the optical cavity it is possible to determine a series of interference fringes. Said fringes, which can be measured by means of an optical sensor, allow to identify the cell properties, avoiding the presence of instruments that necessarily require continuous calibration.

[0028] By virtue of the present invention, it is also possible to evaluate more precisely the effects of drugs on contractile cells, such as, for example, cardiac cells. Indeed, cardiovascular diseases prove to be strictly connected to heart muscle dysfunctions. It is thereby possible to determine a more accurate model, compared to the prior art, of a single or a plurality of cardiac cells, thus monitoring the alterations in the contraction, for example following a pharmacological treatment.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Further features and advantages will become fully apparent from the detailed description of a preferred, non-limiting embodiment of a device for interferometrically measuring a contractile cell, shown by way of example in the set of drawings, in which:

[0031] - Figure 1 shows a perspective view of a device and system for interferometrically measuring a contractile cell according to the present invention, in accordance with a first embodiment;

[0032] - Figure 2 shows an operation diagram of the device of Figure 1;

[0033] - Figure 3a shows a perspective view of an interferometric measuring device according to the present invention, in accordance with a second embodiment;

[0034] - Figure 3b shows a sectional side view of the device of Figure 3a.

[0035] DETAILED DESCRIPTION

[0036] Referring in particular to Figure 1, the reference number 1 indicates a device for interferometrically measuring the contraction of at least one contractile cell C.

[0037] The device 1 comprises a transparent substrate 2 comprising a lower face 21 and an opposite upper face 22 coated with a reflective film 23. Further, as shown in Figure 1, the device comprises at least one flexible membrane 3. The at least one flexible membrane 3 is superimposed and spaced apart with respect to the substrate 2 and has a lower surface 31 and an opposite upper surface 32. In other words, the at least one flexible membrane 3 is placed above the substrate 2, such that the substrate 2 and the at least one flexible membrane 3 face one another.

[0038] The upper surface 32 of the at least one flexible membrane 3 comprises at least one zone 34 suitable for culturing at least one contractile cell C. Indeed, the zone 34 has such a shape that, under the necessary conditions, it can simulate the microenvironment of living tissues. For example, each zone 34 acts as a cell culture well.

[0039] The lower surface 31 of the at least one flexible membrane 3 comprises at least one reflective element 33, placed at a respective at least one zone 34 of the upper surface 32.

[0040] Further, the device 1 comprises at least one optical cavity 4 defined between the lower surface of the flexible membrane 3 and said reflective film 23 of the substrate 2.

[0041] In other words, the device of the present invention is based on the concept of optical cavity as defined in the classical optics. Taking a Fabry -Perot interferometer as a reference, optical cavity means an arrangement of reflective surfaces, such as, for example, two or more mirrors. In detail, said arrangement leads to the formation of a resonant cavity for light waves. Indeed, if an incident light wave illuminates the optical cavity, the incident wave undergoes a series of continuous reflections between the two reflective surfaces within the optical cavity, and partially comes out therefrom with each reflection. Within said optical cavity an interference phenomenon thus occurs, thereby forming an interference pattern.

[0042] It is worth noting that the flexible membrane 3 is made of a material having flexibility properties, for example a polymeric material, so that it can be flexible, i.e. subjected to a detectable movement like curving, twisting, or bending, following the contraction of a contractile cell C.

[0043] The flexible membrane 3 can be made of a material selected from silicon nitride, silicon dioxide, aluminium oxide, quartz, silicon carbide, PDMS, or alternative materials having a comparable flexibility. Preferably, the flexible membrane 3 has a flexibility which is substantially equivalent or comparable to that found by cells in the human body, in order to increase the measurement reliability.

[0044] In the preferred embodiment, the flexible membrane 3 has a thickness in the range of hundreds of nanometers. More preferably, the thickness is comprised between 100 nm and 5000 nm.

[0045] The at least one flexible membrane 3 has an extension comprised between 0.01 mm and 5 mm. In particular, in the embodiment of Figure 1, the extension of the at least one flexible membrane 3 is comprised between 0.5 mm and 5 mm. Conversely, in the embodiment of Figures 3a and 3b, the extension of the at least one flexible membrane 3 is comprised between 10 pm and 100 pm, these dimensions being almost equivalent to those of a contractile cell C, in particular of a cardiac cell.

[0046] As previously described, the at least one reflective element 33 is placed at the at least one zone 34 on which at least one contractile cell C is positioned. In other words, the at least one reflective element 33 is under the at least one zone 34 on which the at least one contractile cell C is positioned. In this manner, the cell contraction causes the at least one flexible membrane 3 to bend, which, in turn, leads to a different orientation of the reflective element 33.

[0047] In use, two areas can be identified in the device 1 : an area facing outwards, technically referred to as “trans”, and an opposite area facing inwards, technically referred to as “cis”. Said areas are thus divided due to the presence of the at least one flexible membrane 3, so that the “cis” area can be identified between the at least one flexible membrane 3 and the reflective film 23 of the substrate 2. Conversely, the “trans” area can be identified as the area placed above the at least one flexible membrane 3. In detail, the “trans” area comprises the at least one zone 34 suitable for receiving a culture of contractile cells C.

[0048] Preferably, the at least one reflective element 33 comprises a plurality of mirrors 331 distributed on the lower surface 31 of the at least one flexible membrane 3 according to a predefined pattern. More preferably, the plurality of mirrors 331 is embedded in the lower surface 31 of the at least one flexible membrane 3.

[0049] It is worth noting that the presence of a predefined pattern allows the contraction of the at least one contractile cell C to be evaluated by taking as a reference the orientation of a mirror of the plurality of mirrors 331 facing downwards with respect to the corresponding contractile cell C.

[0050] Note that the aforementioned pattern can be modified in a manner consistent with the parameters which define the optical cavity, such as, for example, the distance between two mirrors. In other words, according to a first embodiment, the device 1 comprises a single flexible membrane 3, preferably made of a material selected from silicon nitride, silicon dioxide, aluminium oxide, quartz, or silicon carbide. Still preferably, the flexible membrane 3 has the aforementioned plurality of mirrors 331 along the lower surface 31.

[0051] In the embodiment of Figure 1, the at least one optical cavity 4 preferably comprises a single optical cavity 4 having a width of 2 mm and a thickness in the range of micrometers. More preferably, said thickness is comprised between 2 pm and 100 pm.

[0052] Still referring to the embodiment of Figure 1, the device comprises a plurality of zones 34 capable of receiving a plurality of contractile cells C.

[0053] According to an aspect, the plurality of zones 34 of the upper surface 32 is placed at the plurality of mirrors 331.

[0054] With more reference to Figure 2, the contraction of one or more contractile cells C causes the flexible membrane 3 to curve and, accordingly, the orientation of the plurality of corresponding mirrors 331 to change. In the presence of an external light source 1, the device 1, said plurality of mirrors 331 and said reflective film 23, which define the optical cavity 4, allow the incident light to be reflected multiple times between the plurality of mirrors 331 and the reflective film 23 itself, thereby forming a plurality of interference fringes.

[0055] Said plurality of interference fringes can be measured by an external optical sensor to detect several properties of the contractile cells C, such as, for example, the contraction force. This aspect will be examined in depth in a method set forth in the following of the present description.

[0056] Advantageously, the pattern on the lower surface 31 of the flexible membrane 3 allows to obtain a more accurate measurement compared to the background art, reducing the crosstalk phenomenon.

[0057] In particular, the plurality of mirrors 331 is engineered so as to make the spatial frequency of the interference fringes originating from the reflection of incident light to correspond. It is thereby possible to detect the phase variations of the interference fringes by observing the mean intensity of the fluorescence reflected by every single mirror 331 of the plurality of mirrors 331.

[0058] In an alternative embodiment, shown in Figure 3a, the device 1 comprises a preferably opaque support membrane 6. Preferably, said support membrane 6 is made of silicon nitride. In the same embodiment, the at least one flexible membrane 3 is made of PDMS or, as an alternative, of preferably polymeric materials having a substantially equivalent flexibility.

[0059] Still preferably, the support membrane 6 has a greater thickness than the flexible membrane 3. More preferably, the thickness of the support membrane 6 is comprised between 100 nm and 100 pm.

[0060] In the same embodiment, the support membrane 6 preferably comprises at least one through-hole 61.

[0061] Referring to Figure 3b, the at least one flexible membrane 3 is preferably superimposed on the support membrane 6 and made in structural continuity with the support membrane 6 at a respective at least one through-hole 61. In other words, as shown in Figure 3b, each flexible membrane 3 is placed to cover a respective through- hole 61 of the underlying support membrane 6.

[0062] Indeed, according to an aspect, the at least one through-hole 61 is shaped in order to be arranged below a single contractile cell C. In other words, in the embodiment of Figures 3a and 3b, the at least one through-hole 61 is placed at the at least one zone 34 of the upper surface 32 of the flexible membrane 3. Each zone 34 is adapted to receive a contractile cell C.

[0063] Still preferably, said at least one through-hole 61 comprises a plurality of through-holes 61 distributed on the support membrane 6 according to a predefined pattern. In the preferred embodiment, the at least one flexible membrane 3 comprises a plurality of flexible membranes 3, wherein said plurality of flexible membranes 3 is arranged at said plurality of through-holes 61. This advantageously allows to evaluate simultaneously the behaviour of a plurality of contractile cells C.

[0064] In other words, the present embodiment comprises a plurality of flexible membranes 3 having the same pattern as the plurality of through-holes 61, so that a flexible membrane 3 of the plurality of flexible membranes 3 corresponds to each through-hole 61 of the plurality of through-holes 61.

[0065] In the embodiment of Figures 3a and 3b, since the plurality of mirrors 331 is embedded in the lower surface 31 of the flexible membrane 3, it consequently lies at the plurality of through-holes 61. That is to say that each flexible membrane 3, placed to cover a through-hole 61, has a respective mirror 331 in its lower surface 31. In the same embodiment, one or more functional units can be defined, each comprising a single through-hole 61, a respective single flexible membrane 3, and a respective single mirror 331.

[0066] It is thereby advantageously possible to determine the contraction of a single contractile cell C in relation to the movement of a single flexible membrane 3. In other words, independent measurements for a single contractile cell C are advantageously allowed, even within a large cell culture.

[0067] In the aforementioned embodiment, the at least one optical cavity 4 has an extension corresponding to the at least one through-hole 61. More preferably, the extension of the at least one optical cavity 4 corresponds to the extension of the flexible membrane 3, i.e. to that of a contractile cell C.

[0068] According to a further aspect, the device 1 preferably comprises a plurality of optical cavities 4, each defined for each through -hole 61. Indeed, a single optical cavity 4 has an extension corresponding to a contractile cell C.

[0069] In the preferred embodiment of the invention, the at least one reflective element 33 is preferably made of gold. More preferably, the plurality of mirrors 331 is made of gold.

[0070] In alternative embodiments, the reflective element can be made of different materials, such as platinum or silver.

[0071] Preferably, the reflective film 23 of the substrate 2 is also made of gold. Still preferably, the reflective film 23 has a thickness corresponding to 100 nm, so as to impart a partial optical transparency adapted to the passage of light reflected by the plurality of mirrors 331. Preferably, a single mirror 331 of the plurality of mirrors 331 has a square shape. Alternatively, it can have a different polygonal shape, for example triangular or circular, or oval / elliptical.

[0072] According to the preferred embodiment, the device 1 comprises a preferably non-volatile liquid 5, interposed between the at least one flexible membrane 3 and the substrate 2. More preferably, said non-volatile liquid 5 fills the at least one optical cavity 4.

[0073] More preferably, the liquid 5 comprises fluorescent molecules and / or quanta 51. In the preferred embodiment, said fluorescent molecules and / or quanta are randomly dispersed in the liquid 5. Preferably, the molecules and / or quanta 51 correspond to molecules of rhodamine, an organic compound capable of absorbing light having wavelengths falling in the ultraviolet and visible range.

[0074] In use, the rhodamine molecules have the property of emitting light, since it is a fluorescent compound. In particular, the rhodamine molecules are thus capable of reflecting light in a different spectrum with respect to the incident light spectrum.

[0075] Preferably, the at least one zone 34 of the upper surface 32 of the at least one flexible membrane 3 comprises a respective porous pad intended to accommodate a contractile cell C. More preferably, the at least one pad it at least partly made of gold.

[0076] In the preferred embodiment, the device 1 comprises a plurality of porous pads having a size of 30 pm and a pitch of 60 pm.

[0077] Advantageously, the presence of said porous pads allows the adhesion of one or more contractile cells C in the at least one zone 34 of the upper surface 32 to be increased. An object of the present invention is also a system 10 for interferometrically measuring the contraction of the at least one contractile cell C.

[0078] As shown in Figure 1, the system 10 comprises a device 1 as previously described. It further comprises a light source 7 configured to illuminate the at least one optical cavity 4 of the device 1 through the lower face 21 of the substrate 2.

[0079] Preferably, the light source 7 comprises a narrow-band excitation beam 71. More preferably, the excitation beam 71 has a bandwidth comprised between 521 ± 10 nm.

[0080] Alternatively, a light source 7 having an incident beam 71 with a different wavelength and a different bandwidth can be used.

[0081] Furthermore, the system 10 comprises an optical detection system 8 configured to capture light that, reflected by the at least one reflective element 33 and by the reflective film 23 of the device 1 when the at least one optical cavity is illuminated by the light source 7, passes through the lower face 21 of the substrate 2, so as to generate a detection signal.

[0082] Preferably, the optical detection system 8 comprises a CMOS camera, i.e. a high-sensitivity camera comprising a CMOS sensor. Being known to the person skilled in the art, the CMOS camera will not be described in the following of the present description.

[0083] Finally, the system also comprises a processing unit 9 in signal communication with the optical detection system 8. The processing unit 9 is configured to return interferometric data as a function of the processed detection signal generated by the optical detection system 8. In other words, the processing unit 9 is in signal communication with the CMOS camera and it is also capable of evaluating the contractile force of at least one cell C by processing the interference data captured by the optical detection system 8.

[0084] It is a further object of the present invention a method for performing an interferometric measurement of the contraction of a contractile cell C by means of the system 10 described above.

[0085] The method of the present invention comprises the step a) of arranging at least one contractile cell C on a respective at least one zone 34 of the upper surface 32 of the at least one flexible membrane 3.

[0086] The method further comprises the step b) of illuminating the at least one optical cavity 4 of the device 1 by means of the light source 7. As previously described, the light source 7 emits an incident light beam 71 passing through the lower surface 21 of the substrate 21, since it is transparent. The incident light beam 71 illuminates the at least one optical cavity 4 of the device 1 and, following the reflection it undergoes, generates an interference pattern. The interference pattern is obtained in relation to the orientation the at least one reflective element 3 undergoes following the contraction of one or more contractile cells C.

[0087] Next, the method comprises the step c) of generating a detection signal by measuring the fluorescent intensity variation at the at least one reflective element 33 of the device 1 by means of the optical detection system 8.

[0088] In other words, it is possible to measure the variation of the fluorescent intensity, i.e. of the reflected light, below the at least one reflective element 33 during the contraction of one or more contractile cells C positioned on the upper surface 32. In particular, the movement between interference fringes depends on the curvature the at least one flexible membrane 3 undergoes along the horizontal plane. More in detail, the movement between interference fringes is related to the phase change of the reflected light.

[0089] Next, the method according to the present invention comprises the step d) of calculating the interferometric measure of the contraction of the at least one contractile cell C by processing the fluorescent intensity variation measured in the previous step.

[0090] In other words, the movement of the interference fringes evaluated in the previous step is used to quantify the curvature of the at least one flexible membrane 3 associated with the movement of the fringes themselves.

[0091] Preferably, the step of calculating the interferometric measure of the contraction of the at least one contractile cell C involves using a 2D electromagnetic simulation software. More preferably, it involves using a finite element software, such as, for example, COMSOL Multiphysics.

[0092] Preferably, the step of calculating the interferometric measure of the contraction of the at least one contractile cell C comprises a first sub-step of performing a simulation under ideal conditions. Ideal conditions means that the at least one flexible element 3, more preferably the plurality of mirrors 331, is arranged parallel to the reflective film 23 of the substrate 2, i.e. parallel to a horizontal plane. This simulation is thereby used as a reference standard.

[0093] Next, the present step of calculating the interferometric measure of the contraction of the at least one contractile cell C comprises a second sub-step of performing a simulation, wherein the lower surface 31, comprising the plurality of mirrors 331, of the at least one flexible membrane 3 is bent with a radius of curvature ranging between 50 and 150 nm. It is thereby possible to obtain a direct correlation between the curvature of the at least one flexible membrane 3 and the movement of the interference fringes.

[0094] Preferably, the step of calculating the interferometric measure of the contraction of the at least one contractile cell C by processing the variation of the measured fluorescent intensity involves the step of estimating the contraction force of the at least one contractile cell C.

[0095] In other words, once the relation between the curvature of the at least one flexible membrane 3 and the movement of the interference fringes is obtained, it is possible to obtain an estimate of the contraction force of the at least one contractile cell C which made the at least one flexible membrane 3 to curve.

[0096] Preferably, the further step of estimating the contraction force of the at least one contractile cell C involves using a finite element model. More preferably, the step involves using a 2D mechanical simulation model, such as, for example, COMSOL Multiphysics. This software takes the mechanical properties, in particular relating to the curvature of the at least one flexible membrane 3, as an input, and returns an estimate of the contractile force which caused the curvature as an output.

[0097] According to an embodiment of the device 1 previously described, the device 1 comprises the plurality of through-holes 61 and the corresponding plurality of flexible membranes 3 in structural continuity with the support membrane 6. In this case, it is worth noting that the cell contraction of a contractile cell C causes the flexible membrane 3, corresponding to the through-hole 61 on which said contractile cell C is positioned, to curve. Thus, said plurality of flexible membranes 3 can be configured in the form of an array, and the curvature of each flexible membrane 3 can be simultaneously measured by a single optical detection system 8.

Claims

CLAIMS1. A device (1) for interferometrically measuring the contraction of at least one contractile cell (C), characterized by comprising:- a transparent substrate (2) comprising a lower face (21) and an opposite upper face (22) coated with a partially reflective film (23);- at least one flexible membrane (3), superimposed and spaced apart with respect to the substrate (2), having a lower surface (31) and an opposite upper surface (32), wherein the upper surface (32) comprises at least one zone (34) suitable for culturing at least one contractile cell (C), and the lower surface (31) comprises at least one reflective element (33), placed at a respective at least one zone (34) of the upper surface (32),- at least one optical cavity (4) defined between the lower surface of the flexible membrane (3) and said reflective film (23) of the substrate (2).

2. The device (1) according to claim 1, wherein said at least one reflective element (33) comprises a plurality of mirrors (331) distributed on the lower surface (31) of the at least one flexible membrane (3) according to a predefined pattern.

3. The device (1) according to claim 1, comprising a support membrane (6) comprising at least one through-hole (61), the at least one flexible membrane (3) being superimposed on the support membrane (6) and in structural continuity with the support membrane (6) at a respective at least one through-hole (61).

4. The device (1) according to claim 3, wherein said at least one through-hole (61) comprises a plurality of through-holes (61) distributed on the support membrane (6) according to a predefined pattern, wherein the at least one flexible membrane (3) comprises a plurality of flexible membranes (3), wherein said plurality of flexible membranes (3) is arranged at said plurality of through-holes (61).

5. The device (1) according to claim 3 or 4, wherein each at least one optical cavity (4) has an extension corresponding to the at least one corresponding through-hole (61).

6. The device (1) according to any one of the preceding claims, wherein the at least one reflective element (33) and the reflective film (23) are made of gold.

7. The device (1) according to any one of the preceding claims 1, comprising a liquid (5) interposed between the at least one flexible membrane (3) and the substrate (2).

8. The device (1) according to claim 7, wherein said liquid (5) comprises fluorescent molecules and / or quanta (51).

9. The device (1) according to any one of the preceding claims, wherein the at least one zone (34) of the upper surface (32) of the at least one flexible membrane (3)comprises a respective porous pad intended to accommodate a contractile cell (C), preferably at least partly made of gold.

10. A system (10) for interferometrically measuring the contraction of at least one contractile cell (C), comprising:- a device (1) according to any one of the preceding claims;- a light source (7) configured to illuminate the at least one optical cavity of the device (1) through the lower face (21) of the substrate (2);- an optical detection system (8) configured to capture light that, reflected by the at least one reflective element (33) and by the reflective film (23) of the device (1) when the at least one optical cavity is illuminated by the light source (7), passes through the lower face (21) of the substrate (2), so as to generate a detection signal;- a processing unit (9) in signal communication with the optical detection system (8), the processing unit (9) being configured to return interferometric data as a function of the processed detection signal.

11. A method for performing an interferometric measurement of the contraction of a contractile cell (C) by means of the system (10) according to claim 10, comprising the following steps: a) arranging at least one contractile cell (C) on a respective at least one zone (34) of the upper surface (32) of the at least one flexible membrane (3);b) illuminating the optical cavity (4) of the device (1) by means of the light source (7); c) generating a detection signal by measuring the fluorescent intensity variation at the at least one reflective element (33) of the device (1) by means of the optical detection system (8); d) calculating the interferometric measure of the contraction of the at least one contractile cell (C) by processing the optical detection signal generated in the previous step.

12. The method according to claim 11, in which the step of calculating the interferometric measure of the contraction of the at least one contractile cell (C) involves the further step of estimating the contraction force of the at least one contractile cell (C).

13. The method according to claim 12, wherein the further step of estimating the contraction force of the at least one contractile cell (C) involves using a finite element model.

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