Modular sensor-actuator

Abstract

The present invention relates to a sensor-actuator (10) comprising at least two modules (12, 14) including: - a core (18) designed to expand and generate forces under the effect of an environmental stimulus such as heat or humidity, - a fibrous network (20) surrounding the core (18) so as to constrain the expansion of the core (18) to favor deformation along at least one axis of extension, bending, or torsion, the sensor-actuator (10) being such that, among the two modules (12, 14): - the first end (30) of the core (18) of the first module (12) includes a female assembly portion (34), and - the second end (32) of the core (18) of the second module (14) includes a male assembly portion (36) adapted to cooperate with the female assembly portion (34) of the first module (12) to assemble the first module (12) to the second module (14). Figure for the abridged version: 2

Description

Title of the invention: Modular sensor-actuator Technical field of the invention

[0001] The present invention relates to the field of sensors and actuators in the context of frugal robotics which are capable of sensing environmental changes and reacting to them by deforming or exerting effort.

[0002] The invention relates more particularly to an assembleable and modular sensor-actuator and to a method for manufacturing such a sensor-actuator. Technical background

[0003] In the field of frugal robotics, sensor-actuators that use stimuli from the environment as an energy source are known.

[0004] The stimuli may be, for example, a change in ambient temperature or humidity.

[0005] Classically, such sensor-actuators are designed to deform in response to a variation in temperature or humidity of the medium in which the sensor-actuator is located.

[0006] These sensor-actuators are designed to enable specific movements, which can be carried out in certain directions or around certain axes. Thus, for each need, a new sensor-actuator must be developed.

[0007] However, there is an advantage to having a sensor-actuator that can be adapted to any type of movement and effort. Summary of the invention

[0008] The invention proposes a sensor-actuator comprising at least two modules, of which a first and a second module, each module comprising: - a core extending along a principal direction of elongation between a first end and a second end and designed to expand and generate stresses under the effect of an environmental stimulus such as heat or humidity, - a fibrous network enveloping the core so as to constrain the expansion of the core to favor deformation along at least one axis of extension, bending or torsion, the actuator being such that among the two modules, - the first end of the kernel of the first module includes a female assembly portion, and - the second end of the core of the second module has a male assembly portion capable of cooperating with the female assembly portion of the first module to assemble the first module to the second module.

[0009] According to other features of the invention: - the core comprises a main cylindrical body; - the nucleus comprises a main tubular body; - the core is made of polymer; - the core is made of metal; - the fibrous network is made of composite material comprising mineral fibers such as carbon or basalt fibers and a polymer matrix acting as a binder; - the fibers form a helical winding along the nucleus in the principal direction of elongation; - the inclination of the fibers relative to the principal direction of elongation and the spacing between the fibers of a module are configured to obtain a predetermined deformation by torsion around the principal axis of elongation; - the core of a module has a length, diameter and wall thickness configured to obtain a predetermined deformation by torsion around the principal axis of elongation; - the core of a module has a lateral notch configured to obtain deformation by bending around an axis perpendicular to the main axis of elongation; - the actuator sensor includes a locking mechanism for the module assembly.

[0010] The invention also relates to a solar tracker comprising a sensor-actuator according to the invention, the core of a module being capable of expanding under the effect of solar heat.

[0011] The invention also relates to a method for making a module of an actuator characterized in that it comprises the following steps: - El: production by additive manufacturing or extrusion of a polymer core extending along a principal direction of elongation between a first end and a second end, - E2: fabrication, at the first end of the core, of a portion of female assembly, - E3: realization, at the second end of the core, of a male assembly portion capable of cooperating with the female assembly portion of another module to assemble the module being realized with the other module; - E4: winding of carbon fibers, basalt or plant fibers soaked in polymer so as to envelop the core of a helical fibrous network extending along a principal direction of elongation.

[0012] The invention also relates to a method for manufacturing an actuator characterized in that it comprises the following steps: - E5: creation of at least two modules according to the process described above, and - E6: assembly of modules involving the insertion of a male assembly portion of one module into a female assembly portion of another module. Brief description of the figures

[0013] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the accompanying drawings in which:

[0014] [Fig.1] is a schematic perspective view of a sensor-actuator before assembly according to an embodiment of the invention;

[0015] [Fig.2] is a schematic perspective view of the sensor-actuator of [Fig.1] after assembly;

[0016] [Fig.3] is a schematic perspective view of a sensor-actuator module of [Fig.1];

[0017] [Fig.4] is a schematic view from below of the module of [Fig.3];

[0018] [Fig.5] is a schematic perspective view of another sensor module- actuator of [Fig.1] having a different shape and function from that of the module of [Fig.3];

[0019] [Fig.6] is a perspective view showing four main core module bodies wrapped in a fibrous network forming a helical winding with different winding angles;

[0020] [Fig.7] is a perspective view showing four main core bodies with different rates of core coverage by the fibrous network;

[0021] [Fig.8] is a bottom view showing four main core bodies with different core wall thicknesses;

[0022] [Fig.9] is a perspective view showing four principal core bodies with different lengths;

[0023] [Fig. 10] is a partial perspective view of a solar tracker according to one embodiment of the invention;

[0024] [Fig. 11] is a flowchart of a method for making a module of a sensor-actuator according to the invention;

[0025] [Fig. 12] is a schematic perspective view of a rotating 3D (three-dimensional) printer winding the fibers of the fibrous network onto the core of a module. Detailed description of the invention

[0026] For the purpose of describing the invention and understanding the claims, the vertical, longitudinal, and transverse orientations of the V, L, T coordinate system shown in the figures shall be adopted, without limitation and without limiting reference to Earth's gravity, in which the longitudinal axis L and transverse axis T extend in a horizontal plane. By convention, the vertical axis is oriented from bottom to top, the longitudinal axis L is oriented from back to front, and the transverse axis is oriented from right to left.

[0027] In the description that follows, identical, similar or analogous elements will be designated by the same reference numerals.

[0028] Figures 1 and 2 illustrate a sensor-actuator 10 according to a first embodiment of the invention.

[0029] In the example shown, the sensor-actuator 10 comprises three modules: a first module 12, a second module 14, and a third module 16. In [Fig. 1], the three modules 12 to 16 are disconnected and thus clearly separated from one another. In [Fig. 2], the three modules 12 to 16 are assembled, that is, nested one inside the other. The sensor-actuator may include a locking mechanism for the module assembly, such as a lug that engages against a stop by rotation or a weld that secures the two modules together.

[0030] Fig. 3 represents one of the modules, for example, the first module 12 or the second module 14.

[0031] The module 12, 14 comprises a central core 18 which gives its structure to the module 12, 14 and a peripheral fibrous network 20 applied to the core 18.

[0032] The core 18 extends along a principal vertical elongation direction D. In the example, the core 18 has a general cylindrical shape and D constitutes the central axis of revolution symmetry of the core 18.

[0033] Nucleus 18 exhibits a strong ability to expand in response to an environmental stimulus. This ability to expand is measured by a dilation coefficient.

[0034] The coefficient of expansion measures the relative increase in volume when only one parameter corresponding to the stimulus is varied.

[0035] Depending on the intended application of the sensor-actuator, the stimulus may be, for example: - heat and in this case, the core has a high coefficient of thermal expansion, - humidity and in this case, the core has a high hygroscopic expansion.

[0036] Thermal expansion is the tendency of matter to change volume in response to changes in temperature. When a substance is heated, its particles move more and thus maintain a greater average separation. Thermal expansion results in an increase in the volume of a body.

[0037] By way of illustration only and in no way limiting, the core may have a coefficient of thermal expansion greater than 10⁶ K*. The materials selected to make a core capable of expanding with heat are, for example, polymers or metals.

[0038] The temperature can be induced directly by a variation of environmental conditions or indirectly by Joule effect when the material is conductive.

[0039] Water expansion corresponds to the change in volume of a material with the absorption of water during a change in humidity in the surrounding atmosphere. Indeed, a difference in water concentration in a material can lead to a change in the volume of that material via a difference in density.

[0040] This capacity for water or hygroscopic expansion of a material can be measured by characterizing the hygroscopic expansion as a function of the evolution of the material's water content, by measuring the water absorption isotherm, which corresponds to a curve representing the expansion at a given temperature. The curves of materials of interest for manufacturing the sensor-actuator have a relatively steep slope.

[0041] Ambient humidity, or hygrometric degree, corresponds to the ratio of the partial pressure of water vapor contained in the air to the saturation vapor pressure at the same temperature. It is therefore a measure of the ratio between the water vapor content of the air and its maximum capacity to hold water vapor under these conditions. This ratio depends not only on the temperature but also on the pressure.

[0042] The highly hygroscopic materials selected to make a core capable of expanding with humidity are, for example, synthetic polymers.

[0043] The core 18 can also be made of composite material.

[0044] The core 18 can be, for example, a tube or a mandrel.

[0045] The fibrous network 20 is made by means of fibers 22 wound around the core 18 so as to envelop the nucleus 18. In the example shown, the fibrous network 20 is wound around a peripheral lateral face 24, delimiting the circumference of the nucleus. Thus, the fibrous network 20 restricts the radial expansion of the nucleus 18. The expansion of the nucleus 18 will therefore occur mainly along the D axis with regard to extension.

[0046] Furthermore, insofar as the fibers 22 are wound in a helical winding about axis D, the expansion of the core 18 will also cause a twisting movement around the axis D as represented by arrow 26.

[0047] Thus, the fibrous network 20 is arranged so as to constrain the expansion of the core 18 to favor deformation along at least one axis of extension, flexion or torsion.

[0048] The fibrous network 20 can be made of composite material comprising mineral fibers 22 such as carbon or basalt fibers and a polymer matrix forming a binder between the fibers 22 and the core 18.

[0049] In particular, the fibers 22 can be architected inspired by the microstructure of bast plant fibers having a concentric bilaminate shape.

[0050] The core 18 comprises a main body 28 having a first lower end 30 and a second upper end 32.

[0051] The first end 30 has a female assembly portion 34. The second end 32 has a male assembly portion 36.

[0052] In the example shown, the male assembly portion 36 of a module 12, 14, 16 is able to cooperate with the female assembly portion 34 of any other module to assemble the two modules in question.

[0053] Alternatively, a module: - could include a female assembly portion 34 adapted to cooperate specifically with the male assembly portion 36 of another module placed immediately below, and / or - could include a male assembly portion 36 capable of cooperating specifically with the female assembly portion 34 of yet another module, placed immediately above.

[0054] In the example shown, the male assembly portion 36 is a stud 38 projecting from an upper face 40 of the main body 28 of the core 18, the upper face 40 being located at the second end 32 of the main body 28. The stud 38 of the male assembly portion 36 has a cylindrical shape with axis D. The stud 38 may be solid or hollow and open or closed at the bottom and / or top. By way of illustration and not limitation, the stud 38 may have a diameter approximately equal to two-thirds of the diameter of the main body 28 of the core 18. Also by way of illustration and not limitation, the stud 38 may have a height approximately equal to half the radius of the stud 38.

[0055] The female assembly portion 34 is shown in [Fig. 4]. The female assembly portion 34 is formed in a lower face 42 of the main body 28 of the core 18. The lower face 42 has an opening 44 delimited by lateral walls 46. The lateral walls 46 of the opening 44 form part of the female assembly portion 34. The lateral walls 46 are intended to be in contact with a peripheral wall 47 of a stud 38 of a male assembly portion 36 of another module. To prevent relative slippage of two assembled modules, the opening 44 is dimensioned so that the lateral walls 46 delimiting it rub against the peripheral wall 47 of the corresponding stud 38.

[0056] The fibrous network 20 has been shown with a deliberately exaggerated thickness for clarity. The example in [Fig. 4] corresponds to the specific case of a tubular main body 28 with the same internal diameter as the orifice 44. In [Fig. 4], it is visible that the wall of the core 18 has a thickness of l and that the fibrous network 20 has a thickness of em. The dimensioning of the core thickness l and the fibrous network thickness em determines the magnitude of the deformation in response to a given stimulus, as will be shown in [Fig. 8].

[0057] [Fig.5] represents a module of the sensor-actuator 10, for example module 16, having a different shape from that of the modules in [Fig.3].

[0058] Module 16 of [Fig.5] differs from module 12, 14 of [Fig.3] in that it has at least one notch 48 in the peripheral lateral face 24.

[0059] In the example shown in [Fig.5], the notch 48 corresponds to a notch extending horizontally along the entire circumference of the core 18 at mid-height between the first end 30 and the second end 32. By way of illustration and in no way limiting, the notch has a depth substantially equal to half the radius of the core 18.

[0060] The notch 48 is formed between two bimetallic ligaments exhibiting in-phase deformations to generate movement in the same direction. Alternatively, the notch 48 can be formed between a ligament generating the movement and another neutral ligament not generating any particular movement.

[0061] The notch 48 allows a bending movement about a horizontal axis A located in the plane of the notch 48 and allows the forces to be directed in a specific way. This bending movement is represented by arrow 50 and corresponds to a situation in which the stimulus comes from the right side of the figure and is oriented along the transverse direction T. This configuration is particularly suitable for spatial applications where the stimulus is not global, since the phenomenon of convection does not occur.

[0062] As shown in [Fig.5], module 16 can be hollow.

[0063] The distribution of the fibers 22 is adjusted to obtain the desired deformations and forces.

[0064] Figures 6 to 9 show different configurations of main bodies 28 with cores 18 wrapped in a fibrous network 20. In each figure, four examples of main bodies 28 with cores 18 wrapped in a fibrous network 20 are given, and only one parameter varies in the design of these four examples. Varying this parameter allows for a different deformation of the modulus in response to a given stimulus.

[0065] Figure 6 shows main bodies 28 of core 18 enveloped by a fibrous network 20 forming a helical winding along the core in the direction The principal elongation D is represented by an angle α relative to the direction D, varying between 10° (left example) and 60° (right example). Table 1 below shows experimental measurements of the torsion rate with temperature (dtors ion / dT) and the percentage elongation (AL / L) for each angle α.

[0066] [Tables 1] ad tors ion / dT AL / L 10° 4.0 102 ± 2.4 103 °.°C 1 29% 35° 10.7 102 ± 6.0 103 °.°C 1 26% 45° 10.8 102 ± 3.4 103 °.°C 1 16% 60° 10.7 102 ± 2.3 103 °.°C 1 14%

[0067] The measurements in Table 1 show that the torsion rate dtorsion / dT is more than twice as low for an angle of 10° as for angles from 35° to 60°, for which the torsion rate is approximately equivalent. Conversely, the higher the angle α among the winding angles studied, the lower the elongation. In particular, the elongation is approximately half as high for an angle α of 60° as for an angle α of 10°. Thus, an angle α of 35% appears to be the best compromise tested because it allows for both a large torsion angle and a large elongation.

[0068] Figure 7 shows principal bodies 28 of nucleus 18 enveloped in a lattice fibrous 20 forming a helical winding along the core in the principal direction of elongation D with a constant angle α of 35° and with a coverage ratio of the core 18 by the fibrous network 20 varying between 10° (left example) and 60° (right example) of the peripheral lateral face 24. Table 2 below shows experimental measurements of the twist ratio with temperature (dtors ion / dT) and percentage of elongation (AL / L) for each coverage ratio of the core 18 by the fibrous network 20.

[0069] [Tables2] Core coverage by the fibrous network d twist ion / dT AL / L 10% 3.5 102 °.°C 1 35% 35% 11.8 102 °.°C 14% 45% 12.2 102 °.°C 1 16% 60% 12.0 102 °.°C 1 15%

[0070] The measurements in Table 2 show that the torsion ratio dtorsion / dT is approximately three times lower for a core 18 coverage ratio by the fibrous network 20 of 10% than for coverage ratios of 35% to 60%, for which the torsion ratio is approximately equivalent. As for elongation, it is more than twice as high for a 10% coverage ratio as for coverage ratios of 35% to 60%, for which the elongation is approximately equivalent. Thus, to obtain a high torsion angle, coverage ratios greater than or equal to 35% should be preferred, and to obtain high elongation, coverage ratios less than 35% should be preferred.

[0071] Figure 8 shows main bodies 28 of core 18 wrapped with a fibrous network 20 forming a helical winding along the core in the principal direction of elongation D with a constant angle α of 35°, with a constant core 18 coverage ratio of 35% by the fibrous network 20, and with a core wall thickness α of varying such that the ratio of the fibrous network thickness 20 to the core wall thickness α of the core 18 varies between 100% (left example) and 6% (right example). Table 3 below shows experimental measurements of twist rate with temperature (dtors ion / dT) and percentage elongation (AL / L) for each em / α ratio.

[0072] [Tables3] £ m / £ nd twist ion / dT AL / L 6% 9.0 102 °.°C 1 12% 25% 11.8 102°.^1 16% 75% 10.9 102 °.°C 1 16% 100% 13.8 102 °.°C 1 10%

[0073] The measurements in Table 3 show that the torsion rate dtorsion / dT is slightly lower for an em / en ratio of 6% and slightly higher for an em / en ratio of 100% compared to the torsion rates dtorsion / dT for ratios of 25% and 75%. Conversely, the elongation is slightly lower for em / en ratios of 6% and 100% than for em / en ratios of 25% and 75%. During these tests on the wall thickness of core 18, the torque generated during deformation with heat was measured. For an em / en ratio of 6%, the torque remained below 10 Nmkg⁻¹ regardless of the temperature, while for em / en ratios from 25% to 100%, the torque was greater than 20 Nmkg⁻¹ at 100°C, therefore twice as high. For em / en ratios between 25% and 75%, the torsion angle and elongation are little impacted by the thickness of the core wall 18 and the torque obtained is satisfactory.

[0074] Figure 9 shows main bodies 28 of core 18 wrapped with a fibrous network 20 forming a helical winding along the core in the principal direction of elongation D with: - a constant angle α of 35°, - a constant coverage of the core 18 by the fibrous network 20 of 35%, - a constant wall thickness α of the core 18 with an em / α ratio of 50%, - a constant diameter B of the main body 28 of 2 cm, and - a length C of the main body 28 in the direction D varying such that the length-to-diameter ratio C / B of the main body 28 varies between 7 (right example) and 1.5 (left example). Table 4 below shows experimental measurements of the twist rate with temperature (dtors ion / dT) and the percentage of elongation (AL / L) for each C / B ratio.

[0075] [Tables4] C / B d twist ion / dT AL / L 1.5 3.4 102 ± 3.0 103 °.°C 1 13 % 3 7.1 102 ± 1.0 103°.^1 14% 5 10.8 102 ± 3.4 103 °.°C 1 16% 7 18.2 102 ±2.0 103°.^1 10%

[0076] The measurements in Table 4 show that the torsion ratio dtorsion / dT increases with the C / B ratio and therefore with the length C of the main body 28. As for the percentage of elongation (AL / L), it remains of the same order of magnitude between 10% and 16%. The angle of torsion and the elongation therefore increase with the length C of the main body 28 of the core 18.

[0077] The examples in Figures 6 to 9 show that it is possible to configure a module to obtain a predetermined deformation, notably through experimental measurements. The predetermined deformations are, for example, a torsion ratio with temperature (dtorsion / dT) and a percentage elongation (AL / L). The parameters for configuring the module are: - the angle α of inclination of the fibers with respect to the principal direction of elongation, - the coverage ratio of the core 18 by the fibrous network 20 or the spacing between the fibers of a module, - the length C of the main body 28 of the nucleus, - the diameter B of the core 18 orthogonally to the principal direction of elongation D, and / or - the wall thickness of the core 18 or the thickness of the fibrous network.

[0078] More generally, the deformation of a module is programmable by the architecture and the choice of materials used.

[0079] Figure 10 shows an example of an assembly of modules 12, 14, 16 forming a Sensor-actuator 10, for example, to create a solar tracker. Modules 12, 14, 16 are assembled in series, that is to say, they are fitted together along the vertical elongation direction D by means of the male assembly portions 36 and female 34.

[0080] In the case of an assembly of modules 12, 14, 16 in series, the deformations obtained in response to a stimulus can be modeled in order to be predictable.

[0081] Such an assembly can, for example, be used to obtain a solar tracker. A solar tracker is a device that allows a heliographic telescope, intended to observe the sun or some of its effects in the atmosphere, or a solar power generation installation, to track the sun according to the principle of the heliostat. This supporting structure includes one or more sensor-actuators that orient the telescope or solar panels to increase their efficiency or productivity.

[0082] The solar tracker aims to orient the telescope or panels towards the Sun in real time, placing them in an optimal position relative to the incidence of solar radiation, i.e., perpendicular to the radiation if possible. Indeed, at any given moment, the position of the Sun depends on the time, latitude, and day of the year. Real-time adjustment makes it possible to substantially increase the efficiency of the telescope and panels.

[0083] Orientation can be done along two axes: - in azimuth, that is to say from east to west, as the day progresses, and - in altitude, that is to say according to the season and the progress of the day.

[0084] By means of a suitable combination of modules 12, 14, and 16, a solar tracker 54 can be obtained in the form of a foot that rests stably on the ground or is fixed to the ground at its base 56. The upper end 58 is fixed to the telescope or solar panels 60. The sensor-actuator 10 is integrated into the foot of the solar tracker 54 and constitutes, for example, its structure. The deformation of the sensor-actuator 10 under the effect of the sun's heat allows the telescope or solar panels 60 to be automatically oriented along two axes. Such a solar tracker 54 does not require any energy input other than that from the sun and / or variations in humidity, and in particular does not require additional sensors and control systems. It can be used for space installations where operation relies on temperature stimulation.

[0085] The invention relates to a method for manufacturing a module of a sensor-actuator. The flowchart of such a method is shown in [Fig. 11]. The method for manufacturing a module of an actuator comprises the following steps: - El: fabrication of a core extending along a principal direction of elongation between a first end and a second end in polymer by additive manufacturing or by extrusion, - E2: fabrication, at the first end of the core, of a portion of female assembly, - E3: realization, at the second end of the core, of a male assembly portion capable of cooperating with the female assembly portion of another module to assemble the module being realized with the other module; - E4: winding of carbon fibers, basalt or plant fibers soaked in polymer so as to envelop the core of a helical fibrous network extending along a principal direction of elongation.

[0086] Step E1 can be carried out using a 3D printer that deposits successive layers of the core. Alternatively, step E1 can be carried out by extrusion, in which the polymer material is liquefied and forced through a die to give it its cylindrical or tubular shape.

[0087] Step E2 can be performed during additive manufacturing or extrusion when the female assembly portion is directly formed from the shape of the first end of the core. Alternatively, it can be performed by machining or by adding a fitting incorporating the female assembly portion. The fitting incorporating the female assembly portion can be either fitted or bonded.

[0088] Similarly, step E3 can be performed during additive manufacturing or extrusion when the male assembly portion is directly formed from the shape of the first end of the core. Alternatively, it can be performed by machining or by adding a tip incorporating the male assembly portion. The tip incorporating the male assembly portion can be either fitted or bonded.

[0089] Figure 12 represents step E4 of winding the fibers onto the core 18. This step E4 can be carried out using a machine 62 such as a rotary printer or a three-dimensional (3D) printer comprising: - a rotation axis 64 on which the core 18 is rigidly fixed, and - a head 66 capable of depositing fibers 22 of the fibrous network 20 by means of a tip 68. The head 66 is movable in translation along a translation axis 70 parallel to the rotation axis 64 and located immediately above it.

[0090] To carry out the winding of the fibers 22, the rotation axis 64 drives the core 18 in rotation and the head 66 is driven in translation along the translation axis 70 while the fibers are deposited on the peripheral lateral face 24 of the core 18.

[0091] The invention also relates to a method for manufacturing an actuator comprising the following steps: - E5: production of at least two modules according to the process for producing a module of an actuator comprising steps E1 to E4, and - E6: assembly of modules involving the insertion of a male assembly portion of one module into a female assembly portion of another module to achieve a series connection of the modules.

[0092] Step E6 is for example carried out by means of an assembly comparable to that of assembly sets comprising interlocking bricks.

[0093] The assembly of the modules may also include a locking step to prevent the modules from separating. Locking solutions have been described previously.

[0094] The manufacture of the actuator may also include steps for putting the modules in parallel as in the example of [Fig. 10].

[0095] The invention has several technical advantages which are presented below.

[0096] The invention enables the creation of transportable and modular structures tailored to each specification, particularly thanks to the modularity afforded by the ability to assemble modules designed to achieve a specific unit deformation. The modular actuator of the invention makes it possible to obtain a complex movement by decomposing this complex movement into a plurality of unit deformations performed by each module.

[0097] The invention also makes it possible to obtain actuators comprising easily recyclable components.

[0098] The actuator of the invention is particularly robust and reliable insofar as no electronics are required for its operation. The causes of failure are therefore extremely reduced.

[0099] The invention also allows for easy maintenance of the actuator thanks to a particularly simple structure. In the event of a defective module, it is very easy to remove the faulty module and replace it with a functional one thanks to the snap-fit ​​assembly mechanism.

[0100] In addition, the invention proposes an actuator which can be used in extreme conditions and in particular in space, notably thanks to its autonomous character.

[0101] The invention is particularly suited to the design of autonomous solar trackers.

[0102] The invention can nevertheless be used for the manufacture of any adaptive system, that is to say, any system traditionally composed of sensors and actuators that allow the system's configuration to be adapted to an environmental stimulus. The invention is particularly applicable to adaptive systems that must perform rotation with associated forces.

[0103] Legend

[0104] 10 actuator 12 First Module 14 second module 16 third module 18 nucleus 20 fiber network 22 fiber 24 peripheral lateral face 26 torsional movement 28 main body 30 first end 32 second end 34 female assembly portion 36 male assembly portion 38 plot 40 top face 42 lower face 44 orifice 46 side walls 47 peripheral wall 48 notch 54 solar tracker 56 base 58 upper end 60 solar panel or telescope 62 machine 64 axis of rotation 66 heads 68 tip 70 axis of translation of the head D principal direction of elongation a angle of inclination of the fibers in core wall thickness em thickness of the fibrous network B diameter of the main body C length of the main body

Claims

Demands

1. Sensor-actuator (10) comprising at least two modules (12, 14), of which a first (12) and a second (14) module, each module comprising: - a core (18) extending along a principal elongation direction (D) between a first end (30) and a second end (32) and being designed to expand and generate forces under the effect of an environmental stimulus including heat or humidity, - a fibrous network (20) enveloping the core (18) so as to constrain the expansion of the core (18) to favor deformation along at least one axis of extension, bending or torsion, the sensor-actuator (10) being characterized in that among the two modules (12, 14), - the first end (30) of the core (18) of the first module (12) comprises a female assembly portion (34),and - the second end (32) of the core (18) of the second module (14) has a male assembly portion (36) adapted to cooperate with the female assembly portion (34) of the first module (12) to assemble the first module (12) to the second module (14), and the core (18) of a module (12, 14, 16) having a lateral notch (48) configured to obtain a bending deformation about an axis perpendicular to the principal elongation axis (D).

2. Sensor-actuator (10) according to claim 1, characterized in that the core (18) comprises a cylindrical main body (28).

3. Sensor-actuator (10) according to any one of the preceding claims, characterized in that the core (18) comprises a tubular main body (28).

4. Sensor-actuator (10) according to any one of claims 1 to 3, characterized in that the core (18) is made of polymer.

5. Sensor-actuator (10) according to any one of claims 1 to 3, characterized in that the core (18) is made of metal.

6. Sensor-actuator according to any one of claims 1 to 5, characterized in that the fibrous network (20) is made of composite material comprising mineral fibers (22) such as carbon or basalt fibers and a polymer matrix providing a binder.

7. Sensor-actuator (10) according to the preceding claim, characterized in that the fibers (22) form a helical winding along the core (18) along the main elongation direction (D).

8. Sensor-actuator (10) according to the preceding claim, characterized in that the inclination of the fibers (22) with respect to the principal elongation direction (D) and the spacing between the fibers (22) of a module (12, 14, 16) are configured to obtain a predetermined torsional deformation around the principal elongation axis (D).

9. Sensor-actuator (10) according to any one of the preceding claims when it depends on claim 3, characterized in that the core (18) of a module (12, 14, 18) has a length (C), a diameter (B) and a wall thickness (eN) configured to obtain a predetermined torsional deformation around the principal elongation axis (D).

10. Sensor-actuator (10) according to any one of the preceding claims, characterized in that it includes a locking mechanism for the assembly of modules (12, 14, 16).

11. Solar tracker (54) characterized in that it comprises a sensor-actuator (10) according to any one of claims 1 to 10, the core (18) of a module (12, 14, 16) being capable of expanding under the effect of solar heat.

12. A method for manufacturing a sensor-actuator module (10) according to any one of claims 1 to 10, characterized in that it comprises the following steps: - E1: manufacturing by additive manufacturing or extrusion of a polymer core (18) extending along a principal elongation direction (D) between a first end (30) and a second end (32), - E2: manufacturing, at the first end (30) of the core (18), a female assembly portion (34), - E3: manufacturing, at the second end (32) of the core (18), a male assembly portion (36) adapted to cooperate with the female assembly portion (34) of another module to assemble the module being manufactured with the other module; - E4: winding of carbon, basalt, or plant fibers (22) impregnated with polymer so as to envelop the core (18) of a helical fibrous network (20) extending along a principal elongation direction (D).

13. Method of manufacturing a sensor-actuator (10) characterized in that it comprises the following steps: - E5: making at least two modules (12, 14, 16) according to the method of claim 12, and - E6: assembly of the modules (12, 14, 16) comprising the insertion of a male assembly portion (36) of one module into a female assembly portion (34) of another module.