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Title:
A PACKAGE, MADE OF BUILDING MATERIAL, FOR A PARAMETER MONITORING DEVICE, WITHIN A SOLID STRUCTURE, AND RELATIVE DEVICE
Document Type and Number:
WIPO Patent Application WO/2013/174946
Kind Code:
A1
Abstract:
A package (15) for devices (100) insertable into a solid structure (300) for detecting and monitoring one or more local parameters is described. The package (15) is made of a building material formed of particles of micrometric or sub-micrometric dimensions. A device (100) for detecting and monitoring one or more local parameters within a solid structure is further described. The device (100) comprises an integrated detection module (1), having at least one integrated sensor (10), and a package (15), having the above-mentioned characteristics, so arranged as to coat at least one portion of the device (100), comprising the integrated detection module (1). A method for manufacturing the device (100), and a system (200) for monitoring parameters in a solid structure (300), comprising such a device (100), are also described.

Inventors:
PAGANI, Alberto (Via Palestro, 6 Nova Milanese, Monza E Brianza, I-20834, IT)
MURARI, Bruno (Via Ardigò 1, Monza, I-20052, IT)
ZIGLIOLI, Federico Giovanni (Via Vittorio Veneto, 6/a Pozzo d'Adda, MILANO, I-20060, IT)
RONCHI, Marco (STMicroelectronics S.r.l, Via C. Olivetti, Agrate Brianza Monza E Brianza, I-20041, IT)
RICOTTI, Giulio (Regione Boriolo, 5/A Broni, Pavia, I-27043, IT)
Application Number:
EP2013/060669
Publication Date:
November 28, 2013
Filing Date:
May 23, 2013
Export Citation:
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Assignee:
STMICROELECTRONICS S.R.L. (Via C. Olivetti, 2 Agrate Brianza, Monza E Brianza, I-20041, IT)
International Classes:
G01D11/24; G01M5/00
Foreign References:
US20020154029A12002-10-24
US7987728B22011-08-02
US6950767B22005-09-27
Attorney, Agent or Firm:
MOZZI, Matteo et al. (Jacobacci & Partners S.p.A, Via Senato 8, Milano, I-20121, IT)
Download PDF:
Claims:
CLAIMS

1 . A package (1 5) for a device (100) suitable to be incorporated in a solid structure for detecting and monitoring one or more local parameters, characterized in that said package (1 5) is made of a building material formed of particles of micrometric or sub- micrometric dimensions (155).

2. The package (15) according to claim 1 , wherein said package (1 5) is substantially isotropic and homogeneous on a millimetric scale.

3. The package (1 5) according to one of the claims 1 or 2, wherein said particles of micrometric or sub-micrometric dimensions (155) comprise microsilica or silica fume particles. 4. The package (1 5) according to any one of the previous claims, wherein said particles (1 55) further comprise magnetic particles.

5. The package (1 5) according to any one of the previous claims, wherein said particles (1 55) comprise cement particles and microsilica or silica fume particles.

6. The package (15) according to any one of the previous claims, comprising:

- a housing portion (151 ), having a housing (150) for an integrated detection module (1 ) comprised in the device (100) ;

- a filling portion (152), shaped to completely coat said integrated detection module (1 ).

7. The package (15) according to claim 6, wherein the housing (1 50) is rotated by a known angle with respect to an axes system of the package (1 5), to determine a predefined positioning of the integrated detection module (1 ), so as to detect at least one of said one or more local parameters, along a corresponding predefined direction, related to the said predefined positioning.

8. A device (100) for detecting and monitoring one or more local parameters within a solid structure (300), comprising :

- an integrated detection module (1 ) having at least one integrated sensor (10); - a package (1 5) arranged to coat at least one portion of the device (100), said portion comprising the integrated detection module (1 ),

and wherein the package (15) is in accordance with any one of the claims 1 -7. 9. The device (100) according to claim 8, wherein the package (15) is arranged with an internal surface thereof (158) in contact with the at least one integrated sensor (10), and with an external surface thereof (157) in contact with a portion of the solid structure (300), so as to separate the at least one integrated sensor (10) from the solid structure (300) and to allow the transferring, to the at least one integrated sensor (1 0) of at least one detectable quantity related to a corresponding parameter, of the one or more local parameters, measured in said portion of the solid structure (300) in contact with the package (1 5).

10. The device (1 00) according to one of the claims 8 or 9, wherein the at least one integrated sensor (1 0) is capable of detecting one or more parameters selected from those of the following group: pressure, temperature, mechanical stress.

1 1 . The device according to claims 9 and 10, wherein the integrated sensor (10) is a temperature sensor, capable of measuring the temperature to which it is subjected by exploiting the phenomenon of the variations of the mobility in the silicon in dependence on the temperature; and wherein said detectable quantity substantially corresponds to an averaged combination of values assumed by the temperature in different points of the solid structure portion in contact with the package (1 5). 12. The device according to claims 9 and 10, wherein the integrated sensor (10) is a pressure or mechanical stress sensor, comprising crystalline material having one or more predefined crystalline axes, said pressure or mechanical stress sensor being capable of measuring the pressure or mechanical stress to which it is subjected, along at least one of the crystalline axes, by exploiting the piezoresistive phenomenon in the silicon and wherein said detectable quantity substantially corresponds to an averaged combination of values assumed by the pressure or mechanical stress, along said at least one crystalline axis, in different points of the solid structure portion in contact with the package (1 5). 13. The device (1 00) according to any one of the claims 8-1 2, wherein: - the integrated detection module (1 ) further comprises an integrated antenna

(1 1 );

- the integrated detection module (1 ) is formed on a single chip;

- the package (15) completely coats said single chip; and

the integrated detection module (1 ) is entirely hermetically sealed and galvanically insulated from the surrounding environment.

14. The device (1 00) according to any one of the claims 8-1 3, further comprising :

- electromagnetic means (2) for transmitting/receiving signals between the integrated antenna (1 1 ) of the integrated detection module (1 ) and a remote antenna

(221 ); said integrated antenna (1 1 ), electromagnetic means (2), and remote antenna (221 ) being able to communicate and transfer energy via a magnetic or electromagnetic coupling in wireless mode;

- support means (3) configured to provide support to the integrated detection module (1 ) and to the electromagnetic means (2), thus making them mutually integral, and further configured to fix the device (1 00) to a supporting structure (21 1 ) passing through the points to be monitored within the solid structure (300) ;

the device (100) being characterized in that the package (1 5) further coats at least one portion of the support means (3).

15. The device (1 00) according to claim 14, wherein said electromagnetic means (2) comprise:

- a first antenna (21 ), configured to communicate with the integrated antenna (1 1 ), via a magnetic coupling for near-field electromagnetic communication;

- a second antenna (22), configured to communicate with the remote antenna

(221 ), via a far-field electromagnetic communication;

connection means (23), configured to connect said first antenna (21 ) and said second antenna (22);

the device (100) being characterized in that the package (15) coats a portion of the support means (3) containing the first antenna (21 ).

16. The device (1 00) according to claim 1 5, wherein the first antenna (21 ) and the second antenna (22) are inclined to each other at any angle between 0 ° and 180 °, to expand or concentrate electromagnetic energy in any corresponding directions.

17. The device (100) according to claim 15, wherein said connection means (23) further comprise a third antenna (251 ), connected via a first transmission line (231 ) to said first antenna (21 ), and a fourth antenna (252) connected via a second transmission line (232) to said second antenna (22), so as to form an electromagnetic expansion and concentration unit (25),

said third antenna (251 ) and fourth antenna (252) being configured to intercommunicate via a magnetic coupling for near-field electromagnetic communication,

said first antenna (21 ) and third antenna (251 ) being inclined to each other at any angle between 0 ° and 180 °, and said second antenna (22) and fourth antenna (252) being inclined to each other at any angle between 0 ° and 180 °, to expand or concentrate electromagnetic energy in any corresponding directions,

the device (100) being characterized in that the package (15) coats a portion of the support means (3) containing said at least one electromagnetic expansion and concentration unit (25).

18. The device (100) according to claim 17, wherein said connection means (23) comprise at least one further electromagnetic expansion and concentration unit, interposed between the third antenna (251 ) and the fourth antenna (252), the at least one further electromagnetic expansion and concentration unit comprising a fifth antenna and a sixth antenna, interconnected, configured to communicate, via a magnetic coupling for near-field electromagnetic communication, respectively with an antenna of an electromagnetic expansion and concentration unit, arranged in cascade upstream the at least one further electromagnetic expansion and concentration unit, and with an antenna of an electromagnetic expansion and concentration unit, arranged in cascade downstream the at least one further electromagnetic expansion and concentration unit,

said fifth antenna and sixth antenna being inclined to each other at any angle between 0 ° and 180 °, in dependence on an inclination of the corresponding antenna connected via a wireless coupling, to expand or concentrate electromagnetic energy in any corresponding directions,

the device (100) being characterized in that the package (15) coats a portion of the support means (3) containing also said at least one further electromagnetic expansion and concentration unit.

19. The device (1 00') according to claim 14, further comprising at least one further integrated detection module (1 ") located in the support means (3'), and wherein the electromagnetic means (2) comprise:

- a first antenna (21 '), comprising a coil (21 ') configured to communicate with the integrated antenna of the integrated detection module (1 '), via a magnetic coupling for near-field electromagnetic communication ;

- at least one corresponding further first antenna (21 ") comprising a further coil (21 ") configured to communicate with the integrated antenna of the further integrated detection module (1 "), via a magnetic coupling for near-field electromagnetic communication ;

the coil (21 ') of the first antenna and the further coil (21 ") of the further first antenna being mutually operatively connected in cascade or in parallel or in series; the device (100) being characterized in that the package (15) coats a portion of the support means (3) entirely containing said further integrated detection module (1 "), and said electromagnetic means (2).

20. The device (1 00) according to any one of claims 14-1 9, wherein the package (15) completely coats the device (100). 21 . The device (1 00) according to claim 20, wherein the package (1 5) is conformed to be insertable into a corresponding recess within the solid structure to be monitored (300).

22. The device (1 00) according to claim 20, wherein the package (1 5) is conformed to be insertable into a nail or an expansion screw, said nail and said expansion screw being suitable to be fixed into the solid structure to be monitored (300).

23. System (200) for monitoring one or more parameters in a plurality of points within a solid structure (300), comprising :

- an internal monitoring subsystem (21 0) arranged within the solid structure

(300);

- an external control and data collection subsystem (220) arranged outside and remotely to the solid structure (300);

characterized in that:

- the internal monitoring subsystem (21 0) comprises a supporting structure (21 1 ) passing through the points to be monitored within the solid structure (300), and further comprises a plurality of monitoring devices (100) according to any one of the claims 8 to 22, each of said plurality of monitoring devices (100) being secured to the supporting structure (21 1 ) in a known and predefined position.

24. A method for manufacturing a device (100) for detecting and monitoring one or more local parameters within a solid structure (300), comprising the steps of:

- forming a housing portion (151 ), by using building material made of particles of micrometric or sub-micrometric dimensions (155), in which housing portion (151 ) a housing (150) is arranged;

- inserting an integrated detection module (1 ) of the device (100) into said housing (150);

- forming a filling portion (152), by using building material made of particles of micrometric or sub-micrometric dimensions (155), to make a package (15) arranged to coat entirely the integrated detection module (1 );

- securing said package (15) to support means (3) of the device (100), configured to further support electromagnetic means (2) of the device (100), and further so configured as to fix the device (100) to a supporting structure (21 1 ) passing through the points to be monitored within the solid structure (300).

25. The method according to claim 24, comprising the further steps of:

- forming a further package portion, around a further portion of the device (100) with respect to the integrated detection module (1 ), by injecting building material made of particles of micrometric or sub-micrometric dimensions (155) into a mould (40).

Description:
DESCRIPTION

A PACKAGE, MADE OF BUILDING MATERIAL, FOR A PARAMETER MONITORING DEVICE, WITHIN A SOLID STRUCTURE, AND RELATIVE DEVICE.

TECHNICAL FIELD OF THE INVENTION

Field of Application

The present invention relates to integrated electronic devices for monitoring parameters within a solid structure, and in particular to packages for such devices, having characteristics that are specific for such type of application.

In the invention, a parameter monitoring system, employing the above-mentioned device, within a solid structure, and a manufacturing method of the same device are also included.

Description of the prior art.

In solid structures, particularly in load-bearing structures of, for example, bridges, buildings, tunnels, railways, containment walls, dams, embankments, slabs and beams of buildings, pipelines and underground structures of city underground railways, and so on, it is very important to monitor, in many points, significant parameters, such as, for example, pressure, temperature, and mechanical stresses.

Such a monitoring, carried out periodically or continuously, is useful both in the initial step, and during the life time of the structure.

To this aim, it is known the use of monitoring electronic devices based on electronic sensors, which are capable of providing relatively good performances at low costs. Usually, such devices are applied on the surface of the structures to be monitored, or within recesses already provided in the structure and accessible from the outside.

However, such devices are not generally capable of exhaustively detecting the parameters within the structure to be monitored, which is very useful to know in order to assess the quality of the structure, the safety thereof, its ageing, the reaction to variable atmospheric conditions, and so on.

Furthermore, such devices can only be applied after the structure has been built, and not while it is being built. Therefore, these devices are unable to evaluate possible initial defects.

As a partial response to these desires, the solution shown in the U.S. patent 6,950,767 provides an electronic monitoring device that is entirely contained, i.e., "buried" within the material (for example, reinforced concrete) of which the structure to be monitored is composed. Such a device is a whole system encapsulated in a single container, composed of several parts that are assembled on a substrate, such as integrated circuits, sensors, antennas, capacitors, batteries, memories, control units, and still other substrates, formed in different "chips" that are mutually connected by means of electrical connections consisting in metal connections.

Therefore, on the whole, US 6,950,767 discloses an approach using 'System in Package " (SiP), in which the SiP is coated in a casing of mould material, such as an epoxy resin. The casing is a conventional package, per se known. Such a system communicates with the exterior by virtue of a radio communication subsystem included therein, having antennas of dimensions suitable to communicate with a remote system.

It is noted that a device or a monitoring system intended to operate within a solid structure has to address particular operative conditions. For the present description, solid structures are considered, such as structures made of building material, for example cement, concrete, mortar.

A monitoring device or system intended to be initially "buried" in a building material (e.g., uncured concrete, which will then cure and solidify) and to remain then "buried" in the solid structure, is subjected to very critical operative conditions.

Furthermore, it is in contact with a material having irregularities, from several points of view, due to intrinsic characteristics or imperfections.

All of this causes at least two types of drawbacks, respectively correlated to reliability problems and to possible measurement inaccuracies, which will be investigated below.

Referring to reliability problems, considerable causes for wear are, for example, very high pressures, also of some hundreds of atmospheres, as well as causes related to water seepage, over time, which may damage the system.

A drawback of the known systems, such as the one of US 6,950,767, derives from the fact that they are relatively complex systems, and may be damaged due to the operative conditions in which they have to operate. In particular, the electric interconnections between the various components of the SiP of US 6,950,767 can be vulnerable, due to the mechanical stress to which the SiP inserted in the structure is subjected.

Furthermore, the "window" that has to be left in the package to allow the sensor to detect the corresponding parameter may be a weak point due to possible moisture seepage. Again, a crack or imperfection of the coating material may let water to penetrate within the SiP, causing short-circuits. Besides water, also other substances, such as potentially corrosive acids, can penetrate.

In general, although they are designed for said use, the reliability of systems such as the one of US 6,950,767 has its limit in the complexity of the structure of such a systems, although miniaturized, and the unsuitability of the commonly used known types of package, due to extreme conditions, such as those expected in the applications considered herein.

Referring to problems of incorrect or inaccurate measurement, it may be considered that the solid structure to be monitored is composed of a building material that is never perfectly homogeneous.

For example, concrete is an artificial stone material formed of stone aggregates having different dimensions, referred to also as inerts, which are bonded with cement, as a hydraulic binder activated by chemical reactions with water. Therefore, in concrete it is possible to identify cement granules (having a dimension ranging from 1 to 50 μηι) and a wide variety of granules of inert aggregates, which, quantitatively, can account for up to 80% of the weight. The concrete inert aggregates are usually classified based upon the diameter of the granules thereof, such as very fine, or fillers (diameter < 0,063 mm); fine, or sand/grit (0,063 - 4 mm); coarse (fine gravel/finely crushed stone, 4 - 1 5 mm); gravel/crushed stone (1 5 - 40 mm).

As it is known in the field of building construction, different types of concrete can be obtained with mixtures composed of inert aggregates of different dimensions in various percentages. Such different types of concrete have different characteristics, in terms of properties such as mechanical resistance, porosity, compactness, and lightness. In any case, to obtain a concrete that meets the minimum requirements needed for each of the above-mentioned properties (so that the concrete can be used as a building material for the solid structures here considered), it is always necessary to use a mixture of inert aggregates having different granularities.

As regards in particular to the very fine inerts, microsilica or silica fume is sometimes used, which is composed of particles having a diameter ranging between 0.01 and 1 μηι. Microsilica behaves as a very fine filler, suitable to fill the free spaces between the cement granules, thus increasing the cement compactness. On the other hand, due to the high specific surface of the microsilica particles, they cannot be used in percentages above 1 0%, which would cause the necessity to excessively increase the slurry water amount. In other types of concrete, the fine and very fine aggregates are present in a minimum percentage.

Therefore, it shall be noted that, at a millimetric or sub-millimetric scale, the concrete intrinsically has, due to its nature, irregularities that are randomly distributed within the volume of the solid structure it forms. In addition, there may be local imperfections.

In such conditions, a monitoring device may be considered, for example, arranged in a specific position of a concrete structure, suitable to detect a force (for example, corresponding to a mechanical stress) applied by the solid structure, at a macroscopic level, in that specific position, and along a certain direction, for example, a vertical direction. The device locally detects the force in the point of the surface of an integrated circuit, included therein, in which there is a sensor.

Such a sensor is typically sensible to the piezoresistive effect, and it is capable of measuring a force in a determined direction, which is made to match, in the initial positioning step, to the direction of interest (for example, as said, a vertical one). If the force, while keeping the intensity constant, is applied to a different direction, the sensor sensibility decreases, in accordance with the laws of the piezoresistive effect, and the actually detected force turns out to be lower, sometimes significantly lower.

On the other hand, due to the above-mentioned characteristics of the concrete, the sensor buried in the solid structure may be in contact with a part of the structure having locally very different and inhomogeneous characteristics (presence or absence of micro-cavities, presence or absence of coarse particles, or co-presence of particles having different dimensions, etc.) Such particles exert a punctual action, on a microscopic scale, which may be different from the macroscopic action which should be correctly detected.

In particular, it is possible that the concrete locally exerts a force upon the sensor, through particles having a variable granularity, in a different direction than the macroscopic direction of the force that is to be detected. Consequently, the sensor, due to the characteristics thereof, illustrated above, detects a force intensity that is lower than the actual one.

The described example shows how, by using known devices, particularly severe measurement errors may be originated, even systematic errors.

In brief, if a general known monitoring device is buried within a solid structure, with an integrated circuit without package, inaccuracy problems may arise (or even systematic errors) during the measurements.

If a general known monitoring device is buried within a solid structure, having a package of a common type, severe reliability problems may arise, i.e., high probabilities of damage over time. Also in this case, further measurements errors may originate; for example, the conventional packages may be subjected to a volume reduction following degassing phenomena that can alter, for example, pressure measurements. Furthermore, the interface between the package material and the solid structure material may not allow such an adhesion as to correctly transmit a parameter to be measured.

The object of the present invention is to devise and provide a package for an integrated electronic device to be used to monitor parameters within a solid structure, as well as the monitoring device itself, which are improved so as to at least partially obviate the drawbacks described herein above with reference to the prior art.

In particular, a package and a relative device are proposed, which are simple, have an enhanced robustness and wear resistance, while allowing measurements that are more accurate compared to those allowed by the known packages and devices.

SUMMARY OF THE INVENTION.

Such an object is achieved by a package in accordance with claim 1 .

Further embodiments of the package are defined in dependent claims 2-7.

A monitoring device comprising said package is defined in claim 8.

Further embodiments of such a device are defined in dependent claims 9 to 22.

A monitoring system comprising a device according to the invention is defined in claim 23.

A manufacturing method of the package and the device is defined in claim 24. A further embodiment of such a method is defined in the dependent claim 25.

In particular, a package for a device suitable to be incorporated in a solid structure for the detection and monitoring of one or more local parameters is defined, in which such a package is made of a building material formed of particles having micrometric or sub-micrometric dimensions.

Furthermore, a device for the detection and monitoring of one or more local parameters within a solid structure is defined, such device comprising: an integrated detection module having at least one integrated sensor, and a package so arranged as to coat at least one portion of the device comprising the integrated detection module; wherein the package is made of a building material formed of particles of micrometric or sub-micrometric dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the package and the device according to the invention will be apparent from the description set forth below of preferred implementation examples, given by way of indicative, non-limiting example, with reference to the annexed figures, in which :

- Fig. 1 is a sectional view of a package made of building material and of a part of an electronic monitoring device according to an embodiment of the present invention;

- Figs. 2A, 2B, and 2C are diagrams illustrating some further embodiments of a package made of building material, according to the invention ;

- Fig. 3 is an operational block diagram of an electronic monitoring device according to an embodiment of the invention;

- Fig. 4 is a sectional view of an electronic monitoring device according to a further embodiment of the invention;

- Fig. 5A is a more detailed view of the electronic monitoring device of Fig. 4; - Fig. 5B is an angular diagram of stress sensitivity of a sensor comprised in the monitoring device;

- Fig. 6 is a sectional view of a package and of an integrated detection module comprised in a monitoring device according to a further embodiment of the invention;

- Fig. 7 is a functional block diagram of an electronic monitoring device according to a further embodiment of the invention ;

- Figs. 8, 9, 10 are sectional views of respective further embodiments of a monitoring device according to the invention;

- Figs. 1 1 , 1 2, 13, 14A, 14B, 15A, 15B are diagrams of monitoring devices according to respective embodiments of the invention ;

- Fig. 1 6 is a diagram of a system for monitoring local parameters within a solid structure, according to an embodiment of the invention;

- Figs. 17 and 18 illustrate examples of a package and a monitoring device manufacturing method according to the invention. DETAILED DESCRIPTION.

With reference to Fig. 1 , a package 1 5 for a device suitable to be incorporated in a solid structure for detecting and monitoring one or more local parameters is now described. The device, which will be described in more detail herein below, comprises, besides the package 1 5, at least one integrated detection module 1 having an integrated sensor 10. Preferably, the integrated detection module 1 is formed on a single semiconductor chip (herein below, referred to simply as a chip), that is typically silicon-based.

The package 1 5 is manufactured with a building material formed of particles of micrometric or sub-micrometric dimensions. Such particles are indicated with the reference number 155 in the enlarged sectional view of Fig. 1 .

According to a common language, the terms "particles of micrometric dimensions" define herein particles having a diameter ranging between 1 μηι (μηι = micron, or micrometre) and some tens of μηι; and the terms "sub-micrometric particles" define particles having a diameter equal to or less than 1 μηι.

Preferably, the package 1 5 is formed of particles having a diameter less than 10 μηι.

More preferably, the package 1 5 is formed of particles having a diameter less than 1 μηι.

In accordance with a preferred embodiment, the package 15 is substantially isotropic and homogeneous on a millimetric scale, i.e., a scale from hundreds of μηι to one millimetre and more.

In such a case, the package 15 is formed exclusively (within the limits of the purity that can be obtained) from such particles of micrometric or sub-micrometric dimensions. Furthermore, such particles are distributed in a substantially homogeneous manner, so as to obtain the above-mentioned isotropic property, at least on scales that are larger than the micrometric scale, e.g., on a millimetric scale.

According to a typical embodiment, the particles of micrometric or sub- micrometric dimensions forming the package 1 5 comprise microsilica or silica fume particles, having dimensions ranging, for example, between 0.01 and 1 μηι.

In particular, according to an embodiment, the package 1 5 is made of a building material formed of particles of micrometric or sub-micrometric dimensions 1 55, wherein such particles of micrometric or sub-micrometric dimensions 155 comprise microsilica or silica fume particles, so that said package 15 is isotropic and homogeneous on a millimetric scale.

In accordance with a particular embodiment, the package 1 5 is made of a building material formed from particles of cement and particles of microsilica or silica fume particles.

Advantageously, due to reasons that will be illustrated below, the particles of micrometric or sub-micrometric dimensions can also optionally comprise magnetic particles. An embodiment of the package 1 5, shown in Fig. 2A, comprises a housing portion 151 , having a housing 150 for the integrated detection module 1 , and a filling portion 1 52, shaped to entirely coat the integrated detection module 1 . The housing 1 50 defines, for example, a parallelepiped-shaped recess.

In a further implementation example, illustrated in Fig. 2B, the housing 150 has a recess having a shape that is suitable to guide and facilitate the proper positioning of the integrated detection module 1 within the same recess, for example, the shape of a frustum of a pyramid.

According to a further implementation example, shown in Fig. 2C, the housing 150 is rotated by a known angle a relative to an axes system of the package 15, to determine a predefined positioning of the integrated detection module 1 , in such a way to detect at least one local parameter (for example, pressure) along a corresponding predefined direction, related to the mentioned predefined positioning. In such a case, advantageously, a marker 1 59 is arranged, for example, on the rear part of the package, to indicate such angle, thereby allowing the proper positioning of the integrated detection module 1 within the building structure.

An electronic device 100 for detecting and monitoring one or more local parameters (hereinafter referred to also as a "monitoring device") within a solid structure, according to an example of the present invention, is now described. For this description, reference will be made in particular to Figs. 3 and 4, related to functional and structural aspects of the device 100, respectively.

The monitoring device 1 00 comprises an integrated detection module 1 , having at least one integrated sensor 1 0, and a package 1 5 arranged to coat at least one portion of the device 1 00 comprising the integrated detection module.

As noted before, the integrated detection module 1 is preferably made on a single silicon chip. Therefore, the package 15 fully coats the chip by which the integrated detection module 1 is formed (Fig. 4 shows a sectional view of such full coating).

The package 1 5 is a package having any one of the combinations of characteristics already described above.

In particular, such a package 15 is manufactured with a building material formed of particles of micrometric or sub-micrometric dimensions.

Furthermore, the package 1 5 is preferably substantially isotropic and homogeneous on a millimetric scale.

The monitoring device 1 00 further comprises electromagnetic means 2 for transmitting/receiving electromagnetic signals and energy between the integrated detection module 1 and an external data collection and control system (per se known, not shown in Figs. 3 and 4).

The monitoring device 100 further comprises support means 3, configured to provide a support to the integrated detection module 1 and the electromagnetic means 2 (or electromagnetic circuitry 2), making them mutually integral, and further configured to fix the device 1 00 to a supporting structure 21 1 (which will be illustrated in Fig. 1 6) passing through the points to be monitored within the solid structure. Therefore, the support means 3 allow maintaining the monitoring device 100 in a predefined position within the structure to be monitored.

The support means 3 are formed by an advantageously flexible support 3, for example, made of a polymeric material, on which both the package 15 containing the integrated detection module 1 (for example, by a gluing layer 39) and the electromagnetic means 2 are located.

With reference again to Fig. 3, it shall be noted that the detection module 1 comprises in particular, as noted before, an integrated sensor 10 capable of detecting and monitoring one or more parameters to be controlled, which are characteristic of the structure to be monitored.

Typically, such parameters are a pressure and/or a temperature and/or a mechanical stress. Moreover, it is noted that the detectable parameters may be different from those mentioned above, provided that they have a detectable effect on the semiconductor or on structures integrated in the single chip of which the integrated detection module 1 is composed.

According to various embodiments, the sensors integrated in the integrated detection module 1 can be more than one, and each of them can detect one or more parameters.

The integrated sensor 1 0 is capable of converting a temperature or pressure value into an electrical variable, by exploiting the known variations induced by such parameters, for example, on the mobility of electrons/electron holes in the semiconductor.

In this regard, it is known that the mobility depends on temperature, in a manner that is independent from the crystal orientation of the semiconductor material, and on pressure (or on the force applied) in a manner that is dependent on the crystal orientation of the semiconductor material, according to the laws governing the piezoresistive phenomenon. In particular, with reference to the Miller indices, by using common notations defining planes and axes characterizing a crystal, consider for example a crystal of the N type in the plane (001 ). In such example, the sensitivity to mechanical stress, i.e., the sensitivity to pressure, is maximum if such stress is applied along the axes [1 00] and [01 0] with respect to a reference system associated to the crystal orientation, while it is minimum along the axes [1 10].

Therefore, by means of suitable configurations of the components integrated on the chip of the integrated detection module 1 , it is possible to build pressure sensors, by compensating for the dependence on the temperature, or, vice versa, temperature sensors, by compensating for the dependence on the pressure.

Other dependences on ageing and wear are distinguished from the above- mentioned ones, and are compensated for, taking into account that they emerge over much longer time periods, for example, years.

According to an implementation example, the sensor 1 0 is a pressure sensor formed with four resistors integrated in a Wheatstone bridge configuration, in which two pressure-sensitive resistors are oriented along the axes [100] and [01 0] associated to the crystal orientation, while the other two are oriented along the axes [1 10], which orientation matches with the angle of the axis of minimum sensitivity of the piezoresistive effect. In this way, the dependence of the measurement on the "temperature" parameter is negligible, and in this sense, it is possible to say that the "pressure" parameter is measured in a substantially independent manner from the "temperature" parameter.

According to a further implementation example, the sensor 1 0 is a pressure and temperature sensor made by a first and a second ring oscillator, each comprising a plurality of integrated components (for example, three or an odd number of inverters,) in cascade. The integrated components of the first oscillator are composed of a semiconductor material with a different crystal orientation from the orientation of the material of the second oscillator: for example, respectively, with an orientation along the axis [1 1 0] and [100] or [01 0].

In this way, the oscillation frequency of the first oscillator with orientation at [1 1 0], in which the piezoresistive effect is minimum, substantially depends only on the temperature, the pressure effect being negligible; therefore, such frequency can be seen as the output of a temperature sensor.

The oscillation frequency of the second oscillator with an orientation [100] or [010], if the temperature effect is subtracted, which effect is known by virtue of the output of the first oscillator, substantially depends only on the pressure; therefore, such frequency can be seen as the output of a pressure sensor.

In the examples described above, the presence of membranes or components other than the integrated detection module 1 is not necessary for the operation of the sensor 10.

Referring now to Fig. 5A, it is noted that, in the device 100, the package 1 5 is arranged with an internal surface thereof 158 in contact with the integrated sensor 10, and with an external surface thereof 1 57 in contact with a portion of the solid structure 300 (in the illustrated example, concrete comprising granular particles 310). In this way, the package 1 5 separates the integrated sensor 10 from the solid structure 300, and, at the same time, allows a transfer to such integrated sensor 10 of one or more detectable quantities, related to a corresponding local parameter, and measured in the solid structure portion 300 in contact with the package 1 5.

Thus, on one hand, the package 1 5 is subjected to the action of the solid structure surrounding it (e.g.,, of the part of structure above it); on the other hand, it is capable of transmitting such an action, by contact, to the integrated sensor 10.

It may be considered, for example, the case where, within a concrete structure, a pressure proportional to the intensity of a force applied in a normal direction, for example, a vertical direction, with respect to the integrated detection module (force and direction are indicated by an arrow F' in Fig. 5A) has to be measured.

Taking into account the irregularities and/or non-homogeneities of the structure to be monitored (for example, concrete), it is possible that the force exerted by the structure, on a macroscopic scale, in the above-mentioned normal direction, is instead applied locally, on a microscopic scale, along a different direction. In other terms, the infinitesimal force contributions generated in the examined position by the different infinitesimal concrete regions, having a different consistency and direction in the various points (depending on the local presence of more or less coarse particles 310, or filler, or micro-cavities, etc.) can be combined in such a way to determine a force acting locally in a direction that is different from the normal one.

If the integrated sensor 10 were in direct contact with the concrete (for example, through a window in a traditional package), or were separated therefrom only by a thin passivation layer (for example, silicon), the integrated sensor 10 would directly detect a force exerted locally on a microscopic scale. In case said force, as illustrated above, would act along a different direction from the normal one, i.e., different from that of the crystalline axis of sensitivity of the sensor, the sensor sensitivity would decrease (as illustrated in Fig. 5B in the diagram of angular sensitivity of the sensor, in which the axes of the diagram refer to the orientation of the sensor 1 0 of Fig. 5A). Therefore, this would lead to underestimate the intensity of the force, thus determining an error, even a remarkable error, in the measurement of pressure.

On the contrary, the intermediation carried out by the package 1 5 made of building material cause the various infinitesimal force contributions, transmitted in a random and uneven manner by the concrete in the various points of the package surface, to be substantially averaged out. By virtue of the properties of the package 1 5, illustrated above, the contributions averaged by the package 15 result in a force applied by the package to the integrated sensor 10, in a direction normal thereto (such a force is indicated with an arrow F in Fig. 5A). Therefore, the fact that the sensor 1 0 "receives" the force through the package 15, with which it is in contact, and not directly from the concrete, allows the force to be detected in the direction in which the sensitivity is maximum, thus allowing the pressure to be correctly measured.

According to an embodiment, the integrated sensor 10 is a pressure or mechanical stress sensor, comprising a crystalline material having one or more predefined crystalline axes; such a pressure or mechanical stress sensor is capable of measuring the pressure or the mechanical stress to which it is subjected, along one of the crystalline axes, by exploiting the piezoresistive phenomenon in the silicon. The detectable quantity, transferred from the package 1 5 to the sensor 10, corresponds to an averaged combination of values assumed by the pressure or mechanical stress, along the crystalline axis, in different points of the solid structure portion in contact with the package 15.

In another embodiment, the integrated sensor 10 is a temperature sensor capable of measuring the temperature to which it is subjected, by exploiting the phenomenon of the variations in the mobility in the silicon in dependence on the temperature. The detectable quantity, transferred from the package 15 to the sensor 10, corresponds to an averaged combination of values assumed by the temperature in different points of the solid structure portion in contact with the package 15.

Referring back to the functional diagram of the detection module 1 , reported in Fig. 3, it is noted that it comprises some functional blocks that, on the whole, constitute an integrated circuitry 16.

Such integrated circuitry, besides the sensor 1 0, further comprises an integrated antenna 1 1 .

The integrated antenna 1 1 performs the function of transmitting outside the integrated detection module 1 , in a wireless mode, the measured data, i.e., the intensity of each of the electrical variables depending on and representative of, respectively, one of the physical quantities to be detected and monitored.

The integrated antenna 1 1 further performs the function of receiving operating commands from the outside.

In a particular implementation example, the integrated antenna 1 1 performs the further function of receiving radiofrequency waves necessary for a remote power feeding of the integrated module 1 , without the need for batteries or power supplies in situ.

The integrated antenna 1 1 is made by means of at least one metallization level, for example, in aluminium or copper, comprised in the chip forming the integrated detection module 1 .

The integrated circuitry 16 further comprises, as auxiliary blocks, a power supply circuit 1 2, a driving circuit 13, and a control circuit 14.

The power supply circuit 12 is arranged to obtain the power supply necessary for the operation of the integrated detection module 1 from radiofrequency waves received from the integrated antenna 1 1 .

The driving circuit 13 is arranged to drive the integrated antenna 1 1 so that it wirelessly transmits the measured data.

The control circuit 14 is arranged to control the operation of the integrated functional circuitry present in the integrated module 1 , based upon operating commands sent from the exterior and received by the integrated antenna 1 1 .

The power supply circuit 1 2, the driving circuit 13, and the control circuit 14 can be implemented by means of circuits per-se-known, in the field of smart card production technologies, or of the RFID (Radio Frequency Identification) technology; for example, the integrated antenna 1 1 can operate on the basis of load modulation techniques. Such known aspects are not described in detail herein.

Now, with reference to Fig. 6, some structural details of the integrated detection module 1 are to be noted. In the simplified sectional view of Fig. 6, a silicon sublayer 17 and an integrated circuitry portion 16 are schematically illustrated. The integrated functional circuitry portion 16 is schematized for sake of simplicity only by one layer, but it can of course be made by a plurality of layers, as it is well known.

The silicon sublayer 17 and the integrated functional circuitry portion 1 6 form the single chip on which the integrated detection module 1 is made.

In accordance with a particular embodiment, the chip of the integrated detection module 1 comprises a passivation layer, which is made, for example, of silicon oxide, or silicon nitride, or silicon carbide.

According to an embodiment, the package 1 5 is arranged to completely coat the chip on which the integrated detection module 1 is formed.

In the abovementioned embodiments, the package 15, besides providing a mechanical protection, can act as an impermeable and protective layer against corrosion, so that such module, as a whole, can be entirely hermetically sealed and galvanically insulated from the surrounding environment.

It shall be noted that the complete sealing and the galvanic insulation are made possible by virtue of the fact that all the necessary functionalities for the detection of the parameters to be monitored are realized by blocks that are present within the single chip, forming the integrated detection module 1 . In particular, the integrated detection module 1 , by virtue of the characteristics described above, is advantageously capable of providing its functions without any wire and/or metallization to provide the connections towards the outside of the integrated module itself. Therefore, it does not have any metal terminal, i.e., any wire bonding and/or pad and/or bump towards the outside, thus it can be entirely sealed and galvanically insulated.

Based on the abovementioned features, a complete protection of the integrated detection module 1 can be ensured against water, humidity, and any other corrosion and degradation external agents, avoiding the presence of weak points that may be etched by such agents, such as, for example, metallizations.

Furthermore, as regards the mechanical resistance and the pressure resistance, the required performance is ensured by the mere fact that the package 15 is made of a building material, such as microsilica, which is completely compatible with the material (for example, concrete) of the structure within which the device and the package have to be arranged.

The mentioned characteristics allow the integrated detection module 1 to be embedded in the structure to be monitored during the construction of the same structure, for example, during a casting step of liquid concrete. These characteristics further allow the integrated module 1 to subsequently operate, from within the solid structure (for example, reinforced concrete) after the hardening of the concrete, having a long lifetime and good reliability parameters compared to the typical requirements.

Referring now to Figs. 3 and 7, the electromagnetic means 2 (or electromagnetic circuitry) for transmitting/receiving electromagnetic signals and energy are considered in more detail.

Such electromagnetic means 2 meet the need to allow a communication between the integrated detection module 1 and an external control and data collection system, remotely located, for example at distances of some centimetres or some meters from the structure to be monitored, i.e., from the integrated detection module 1 . This involves transmitting near- or far-field electromagnetic energy, also taking into account the attenuations due to the solid structure through which the electromagnetic fields have to pass.

In view of this, the integrated antenna 1 1 comprised in the integrated detection module 1 cannot per se ensure a remote communication, because of the intrinsic limits mainly due to its reduced dimensions.

In the embodiment described herein, the electromagnetic means 2 allow, by virtue of their own structure, both telecommunications signals to be transmitted/received (for example, transmitting measured data and receiving operating commands for the sensor), as well as an energy exchange to supply power (for example, receiving radiofrequency waves to supply power).

The electromagnetic means 2 perform an electromagnetic expansion and concentration function, i.e., they concentrate an external electromagnetic field, and its related energy, on the integrated antenna 1 1 of the integrated detection module 1 ; and, similarly, they expand an electromagnetic field emitted by the integrated antenna 1 1 , and its related energy, towards a remote antenna.

In particular, the electromagnetic means 2 comprise at least two antennas, a first antenna 21 and a second antenna 22, interconnected by connection means 23. Such connection means 23 can be, for example, a simple transmission line or another circuit (which may comprise, for example, a further electromagnetic expansion/concentration unit, as will be described below). It should be noted that, according to particular implementation examples (one of which is illustrated in Fig. 1 0), the first antenna 21 and the second antenna 22 may be inclined to each other at any angle between 0 ° and 180 °, to correspondingly expand or concentrate electromagnetic energy in any directions.

The first antenna 21 communicates with the integrated antenna 1 1 of the integrated detection module 1 by means of electromagnetic fields (indicated by the symbol E in Fig. 3), and preferably by magnetic field coupling (i.e., near-field magnetic coupling).

The second antenna 22 communicates with a remote antenna, for example of the control and data collection external system, by coupling of electromagnetic fields (i.e., far-field electromagnetic coupling). Each of the first and second antennas 21 , 22 can be a magnetic dipole or a Hertzian dipole, or also another known type of antenna, provided it is capable of performing the above-described functions.

Now, Fig. 7 will be considered, which shows from a structural point of view a monitoring device 100 according to the invention. In particular, Fig. 7 illustrates a further embodiment of the electromagnetic means 2 and the package 1 5.

In the embodiment illustrated in Fig. 7, the first antenna 21 of the electromagnetic means 2 comprises a coil 21 . The connection means 23 of the electromagnetic means 2 comprise an adaptation circuit 23, per se known. The second antenna 22 of the electromagnetic means 2 comprises a Hertzian dipole antenna 22.

The coil 21 is located near the integrated detection module 1 and extends around it, in such a manner as to magnetically couple with the integrated antenna 1 1 . The currents induced by the integrated antenna 1 1 on the coil 21 , acting as a magnetic dipole, are transferred to the Hertzian dipole antenna 22. Such transferring is preferably mediated by the adaptation circuit 23, which may allow improved overall performance of the electromagnetic means 2.

As noted before, the second antenna 22 is in this case a Hertzian dipole, suitable for far field communication. Therefore, the electromagnetic means 2 can be considered in this case as a hybrid transformer, in which a Hertzian dipole is magnetically coupled to the integrated antenna 1 1 .

Advantageously, the magnetic dipole, i.e., the coil 21 , is designed to minimize the dimensions thereof and optimize the coupling to the integrated antenna 1 1 .

Also advantageously, the Hertzian dipole, i.e., the antenna 22, is designed to optimize the far-field communication.

In this regard, the dimensions of the Hertzian dipole antenna are typically comparable to the operative wavelength, which is related to the communication frequency.

According to an exemplary non-limiting implementation example, the monitoring device 100 according to the present invention can utilize a UH F transmission band, at frequencies of about 800 MHz or higher, which implies that it is provided with a Hertzian dipole of reasonable dimensions, of the order of centimetres.

A wide range of frequency bands can be used in several embodiments, finding a balance, according to the specific applications, between the communication to be ensured, on one hand, and the size of the Hertzian dipole considered appropriate, on the other hand. As noted before, the electromagnetic means 2 are capable, based on the same infrastructure already described, not only of transmitting and receiving telecommunications, but also of receiving energy from electromagnetic waves having a suitable power, at frequencies comprised in the operative band of the Hertzian dipole antenna 22. The received energy is used for the remote power feeding of the detection module 1 , via the power supply circuit 1 2.

Various further embodiments of the monitoring device according to the invention will be now illustrated, with reference to different possible arrangements of the package 15.

In accordance with a further embodiment, the device 100 is characterized in that the package 15 further coats at least one portion of the support means 3.

In particular, according to an implementation example, the package 15 coats a portion of the support means 3 containing the first antenna 21 . Such implementation example is also illustrated in Fig. 7, and in Fig. 8 from a structural point of view.

According to another implementation example, the package 15 coats a portion of the support means 3 containing both the first antenna 21 and the second antenna 22 (as illustrated in Fig. 9). It shall be noted that the support portions containing the first antenna 21 (sectional view) are indicated with the reference 3, and the support portions containing the second antenna 22 (not visible in the view of Fig. 9) are indicated with the reference 3' in Fig. 9.

It is noted that, in the implementation examples illustrated in Figs. 8 and 9, a hole 31 is advantageously provided in the support 3, at the position of the integrated sensor in the integrated detection module 1 . Such hole 31 is filled with the building material of the package 15, which can thus transfer in an optimal manner a parameter to be measured to the sensor, according to the principles already described before. In fact, by considering for example a mechanical stress measurement, the presence of the hole 31 in the support 3 at the position of the sensor allows the building material of the package 15 to apply the same force on all the surfaces of the integrated detection module 1 , and therefore the mechanical stress is accurately measured by the pressure sensor.

On the other hand, the need for maximizing the coupling between the integrated antenna 1 1 of the detection module 1 and the first antenna 21 of the electromagnetic means 2 has to be taken into account. Accordingly, the thickness of the support 3 is reduced as much as possible in the region in which such coupling occurs. Furthermore, as shown in Fig. 8 and 9, the hole 31 of the support 3, filled with building material, can be obtained in the central part of the antenna 21 (visible in section) surrounding the integrated detection module 1 .

In order to further improve the magnetic coupling between the two antennas mentioned above, magnetic particles can be advantageously buried at least in a portion of the building material that forms the package 15 and that is contiguous to the two antennas 1 1 and 21 .

According to further implementation examples (one of which is illustrated in Fig. 10), the package 15 fully coats the integrated detection module 1 and the electromagnetic means 2, whatever the nature and number of elements comprised in the latter is.

In the examples set forth above, a portion 32 of the support means 3 intended to constrain the device 100 to a supporting structure (for example, the supporting structure 21 1 set forth in Fig. 16) remains uncoated by the package 1 .

However, according to further embodiments, the package 15 completely coats the device 100. In such a case, the package 1 5 containing the entire device 1 00 can be secured to the supporting structure 21 1 in several ways, for example by gluing or by using tie rods or clamps.

It is noted that different types of devices 100 can be entirely contained in the package 15 according to the invention, for example a device in which the electromagnetic means 2 comprise also at least one electromagnetic expansion and concentration unit 25.

In particular, in the embodiment illustrated in Fig. 1 1 , the connection means 23 of the electromagnetic means 2 comprise a third antenna 251 , connected through a first transmission line 231 to the first antenna 21 , and a fourth antenna 252, connected through a second transmission line 232 to the second antenna 22. The third antenna 251 and the fourth antenna 252 are in turn so configured as to intercommunicate by a preferably magnetic coupling for near-field electromagnetic communication.

The fourth antenna 252, the second transmission line 232, and the second antenna 22 form the already mentioned electromagnetic expansion and concentration unit 25. The second antenna 22 and the fourth antenna 252 are inclined to each other at any angle between 0 ° and 1 80 °, to expand or concentrate electromagnetic energy in any corresponding direction.

In such embodiment, the package 15 coats a portion of the support means 3 containing also the at least one electromagnetic expansion and concentration unit 25.

According to an implementation example, also illustrated in Fig. 1 1 , the electromagnetic means 2 comprise at least one further electromagnetic expansion and concentration unit 25' (structurally similar to the electromagnetic expansion and concentration unit 25) comprising a further fourth antenna 252', connected through a further second transmission line 232' to a further second antenna 253', having the same characteristics of the second antenna 22.

Advantageously, such further electromagnetic expansion and concentration unit 25' performs redundancy functions with respect to the unit 25, so as to enhance the reliability of the device, on the whole, thus increasing its useful lifetime. Accordingly, the further fourth antenna 252' is configured to communicate with the third antenna 251 or with the fourth antenna 252, by a preferably magnetic coupling for near-field electromagnetic communication.

In accordance with another embodiment, the electromagnetic means 2 comprise further electromagnetic expansion and concentration units, mutually arranged in cascade, and interposed between the third antenna 251 and the fourth antenna 252. Similarly to what has been described above, each of the further electromagnetic expansion and concentration units comprises a pair of antennas, in particular a fifth and a sixth antennas, interconnected via a transmission line, and such that one of the antennas is configured to communicate in a wireless mode with a corresponding antenna of a similar electromagnetic expansion and concentration unit arranged upstream ; and the other antenna is configured to communicate in a wireless mode with a corresponding antenna of a similar electromagnetic expansion and concentration unit arranged downstream.

The fifth antenna and the sixth antenna are inclined to each other at any angle between 0 ° and 1 80 °, to expand or concentrate electromagnetic energy in any corresponding direction.

By virtue of this, it is possible to convey the signal generated by the detection module 1 also on relatively long distances, to allow passage through a relatively wide thickness of solid structure, in the case of sensors deeply buried in the structure.

In other implementation examples, included in the invention, different packages 1 5 are provided, each of which being configured to contain one or more of the electromagnetic expansion and concentration units 25.

Advantageously, embodiments in which only one monitoring device comprises a plurality of integrated detection modules are also possible.

For example, a monitoring device 1 00' is illustrated in Fig. 1 2, comprising two integrated detection modules 1 ' and 1 " and further comprising electromagnetic means 2' having three antennas: an antenna 22' for the far-field communication; and two antennas 21 ', 21 ", for the near-field communication. The antennas 21 ' and 21 " are suitable to communicate with the two different integrated detection modules 1 ', 1 " included in the monitoring device 1 00', respectively.

The antennas 21 ' and 21 " for the near field communication can be implemented, respectively, for example by a coil 21 ' and a further coil 21 ", arranged in cascade one to the other, the antenna 21 ' being a quadrupole, formed in the specific example by two semi-coils. The coil 21 ' is directly connected to the antenna 22' ; the further coil 21 " is connected to the antenna 22' via the coil 21 '.

Such an approach can be advantageously applied in the case where two integrated detection modules are used in the same monitoring device, one of which is redundant, so that the operation is not jeopardized in case of damage of one of the two integrated detection modules, in which case the redundant integrated detection module will be used.

Such an approach can also be applied in the case where the two integrated detection modules 1 ', 1 " are two mutually independent modules, provided that an expedient to avoid collisions between the communications relating to the two modules is used. For example, a suitable communication protocol may be applied for avoiding the occurrence of message collisions, as it is known, for example, in the RFID field. Alternatively, the transmission frequencies of the two different integrated detection modules 1 ', 1 " may be distinguished, or the messages for the two different integrated detection modules 1 ', 1 " may be codified in a different manner.

The package 1 5 coats the entire monitoring device 1 00'.

According to a further embodiment, the antennas 21 ' and 21 ", instead of being in cascade to each other, are connected in series or in parallel.

In accordance with further implementation examples, as shown for example in Figs. 14A and 14B, the monitoring device 1 00' comprises a plurality of integrated detection modules and a corresponding plurality of antennas, for example coils, for near-field communication. Each of the connections between such antennas for near- field communication can be in cascade, in series, or in parallel, according to any combinations. The package 15 completely coats the plurality of integrated detection modules and the corresponding plurality of antennas.

With reference to Fig. 14B, a particular implementation example is illustrated, in which the device 100' comprises two end antennas 22' and 22", at the ends of the cascade of antennas 21 of the electromagnetic means 2', on the support 3. Such end antennas can be configured to communicate with a remote antenna, via a far-field electromagnetic coupling, or to communicate, preferably by a magnetic coupling, with corresponding end antennas of similar devices 100' arranged in cascade.

It is noted that, in the implementation example of Fig. 14B, by applying a suitable torque to the support 3, before forming the package 1 5, a helicoidal shape can be determined for such support 3. In this way, the different integrated detection modules 1 can be advantageously oriented differently, allowing each integrated detection module 1 to measure at least one parameter according to a different direction with respect to the other integrated detection modules that are contiguous thereto.

According to alternative embodiments, which are illustrated in Figs. 1 5A and 15B, each integrated detection module 1 can be encapsulated in a pre-package 15' made of building material similar to the package 1 5, according to a corresponding predefined orientation. Such predefined orientation can be obtained by orienting the pre-package 15' according to one or more markers 159' that are present on the support 3 and in accordance with the possible markers 159 indicating the orientation of the integrated detection module 1 contained in the pre-package 1 5' (example illustrated in Fig. 15A) ; or by providing an opening 33 in the support 3, which has its own orientation, corresponding to the desired one, and suitable to house the pre-package 15' containing the integrated detection module 1 (this example is illustrated in Fig. 1 5B).

In a further embodiment, the package 15 fully coats a plurality of devices 100, placed on a common support 30, as shown in Fig. 1 3.

The above-described examples, in which the package 15 fully coats a monitoring device 100, or a plurality of monitoring devices 100, can be implemented, from a structural point of view, in different ways providing for particular configurations of the package 15, particularly suitable to specific applications.

For example, the package 15 can be conformed to be insertable in a corresponding recess within the solid structure 300 to be monitored. This is particularly useful for monitoring devices to be used in ceilings or beams, in slabs, or also in piles for bridges or piling structures. In such a case, by suitably combining the integrated modules (containing the sensors, the corresponding antennas, and optionally the electromagnetic expansion and concentration units), measurements at predefined points in the structure can be obtained, and data can be transferred to antennas arranged in the proximity of an external zone to which the measurement data are to be sent.

According to another example, the package 15 is shaped to be insertable in a nail or a expansion screw; the nail, or the expansion screw, are in turn suitable to be fixed in the solid structure to be monitored. This embodiment is particularly useful for monitoring structures of already existing buildings, for example historical buildings. In an implementation example of the nail, the nail is formed by electromagnetic means having an electromagnetic expansion and concentration function, and optional further electromagnetic expansion and concentration units arranged on a flexible support, which is bent and housed in the package made of building material together with an integrated detection module (in turn, optionally included in a further package made of building material).

In order to insert such nail in the structure to be monitored, a recess is formed therein, in which building material in a semisolid form is then injected. The nail is inserted within such building material (preferably a quick-setting material, thus intended to harden after the insertion of the nail) by using techniques and tools that are known in the building construction field, such as, for example, rubber hammers, or compressed air guns, suitably modified to house such nail.

A system 200 for monitoring parameter within a solid structure is considered with reference to Fig. 1 6, in which the monitoring device 100 and the package 1 5 described above are employed. The monitoring system 200 is capable of monitoring one or more parameters in one or in a plurality of points ("local" parameters), within a solid structure 300 to be monitored.

It should be noted that the illustration of Fig. 16, given by way of illustrative example only, is not in scale. In particular, for sake of illustrative clarity, the relative dimensions of the monitoring devices 1 00 are enlarged therein.

The monitoring system 200 illustrated in Fig. 1 6 comprises an internal monitoring subsystem 21 0 arranged within the solid structure 300, and an external control and data collection subsystem 220 arranged externally and remotely with respect to the solid structure 300.

The internal monitoring subsystem 210 comprises a supporting structure 21 1 passing through the points to be monitored within the solid structure 300, and further comprises a plurality of monitoring devices 100 according to the present invention. Each of the monitoring devices 1 00 is secured to the supporting structure 21 1 in a known and predefined position.

In the example of Fig. 16, the structure to be monitored is a reinforced concrete pillar 300, comprising reinforcing steel rods 301 . Therefore, the internal monitoring subsystem 21 0 is included within such reinforced concrete pillar, starting from the construction step thereof. In the construction step, the internal monitoring subsystem 210 is suitably arranged in a desired position within the volume defined by a formwork. Subsequently, liquid concrete is poured into the formwork, thus surrounding the internal monitoring subsystem 210, and embedding it upon hardening, so that such subsystem is finally "buried" within the reinforced concrete pillar.

The supporting structure 21 1 is suitable to provide support and to secure each of the monitoring devices 100 in a known and predefined position. Such supporting structure 21 1 extends within the solid structure 300.

In the example of Fig. 1 6, the supporting structure 21 1 is a plumb-line, and extends in a rectilinear manner along one dimension of the pillar 300.

In other embodiments, the supporting structure 21 1 can be of any shape, for example rectilinear, along another dimension, or broken, or semicircular, or generically curvilinear, or other shape.

The criteria with which such shape is determined depend on the shape of the structure to be monitored, for example, a curvilinear shape may be suitable to the curvilinear shape of the vault of a tunnel.

It is noted that the shape and positioning of the supporting structure 21 1 determine the geometrical development of the internal monitoring subsystem 21 0, which can be characterized by a very wide range of variations.

The criteria with which the geometrical development of the internal monitoring subsystem 21 0 is determined, in the different embodiments, may depend on the shape of the structure to be monitored and the selection of the significant points to be monitored within the same structure (for example, along one or more axes of the structure, or in points that are particularly sensitive from the structural point of view).

The materials of which the supporting structure 21 1 is made can be various, for example metallic or synthetic.

Again, it is noted that the supporting structure 21 1 , therefore the geometrical development of the internal monitoring subsystem 21 0, may comprise several parts, which are not interconnected, each of which having the characteristics listed above.

One or a plurality of monitoring devices 100 according to the present invention are connected to the supporting structure 21 1 via the support 3. Each of the monitoring devices 100 is secured to the supporting structure 21 1 in a known and predefined position.

In particular, the support 3 can be glued or mechanically constrained to the supporting structure 21 1 in any known way. According to an alternative embodiment, already shown in Fig. 1 3 above, a polymeric material support strip 30 is provided, to be secured to the supporting structure 21 1 , and suitable to house a plurality of monitoring devices 1 00 at predefined distances and in predefined positions.

On a support strip 30, such as the one illustrated in Fig. 1 3, it is possible to place monitoring devices 100 having several types of electromagnetic means 2, different from one another. For example, electromagnetic expansion and concentration elements for far-field communication and electromagnetic expansion and concentration elements for near-field communication may be present. Furthermore, the electromagnetic expansion and concentration elements for far-field communication can have different orientations, to account for the different possible directions at which the electromagnetic signal are received, coming from systems that are external to the solid structure. Therefore, the antennas of such electromagnetic expansion and concentration devices can be for example vertically biased antennas, horizontally biased antennas, and/or antennas orientated according to different angles.

Referring again to the monitoring system 200 illustrated in Fig. 1 6, the external control and data collection subsystem (or "external subsystem" 220) will be now illustrated.

The external subsystem 220 can be advantageously located in a suitable position where the installation is easy, also at a certain distance from the structure to be monitored 300, provided that such distance allows the communication with the internal monitoring subsystem 21 0 and the operation thereof.

Such external subsystem is per se known, therefore it is described herein briefly. The external subsystem 220 comprises one or more external antennas 221 , data collection, storage, and processing means 222, power supplying and remote supplying means 223.

The external antenna 221 is capable of communicating with each of the electromagnetic means 2 of each of the monitoring devices 1 00 comprised in the internal monitoring subsystem 210, so as to thereby implement the already illustrated exchange of telecommunications signals and energy, via electromagnetic fields.

Through the external antenna 221 , the external subsystem 220 receives the data sent by one or any plurality of devices 100 of the internal monitoring subsystem 210, representative of one or more parameters detected and measured by the corresponding sensors 10; the received data are forwarded to the data collection, storage, and processing means 222. Furthermore, via the antenna 221 , the external subsystem 220 sends control signals, for example, commands, to one or any plurality of devices 100 of the internal monitoring subsystem 210; such control signals act, for example, to configure a predefined device 100, and/or to require the measurement of a predefined parameter (at a predefined time or continuously), or other control, configuration, or remote maintenance functions.

For the above-mentioned functions, it is also possible to use communication modes and telecommunication protocols per se known (for example, in the RFID field).

Finally, again via the antenna 221 , the external subsystem 220 sends electromagnetic energy, for example in the form of radiofrequency electromagnetic waves, for the remote power supply of one or any plurality of devices 100 of the internal monitoring subsystem 210.

The data collection, storage, and processing means 222 can be implemented by means of one or more processors, which are physically located together with the other elements of the external subsystem 220, or also arranged remotely and mutually connected via any telecommunications network.

Many different types of processing operations can be performed by such processors, for example, but not limited to: monitoring of the spatial profile of different parameters, with or without interpolation; monitoring of the temporal and historical trends of different parameters; comparison with thresholds to determine possible degradation and danger conditions, and so on.

The power supplying and remote supplying means 223 can include different types of energy generators, based for example on solar cells, or fuel cells, or rechargeable batteries.

Further embodiments of a monitoring system according to the invention comprise the direct insertion into the structure to be monitored of one or a plurality of units, comprising a package made of building material that coats one or a plurality of monitoring devices: for example, in the form of one of the already mentioned nails or expansion screws, containing one or more monitoring devices entirely contained and coated by a package made of building material.

With reference to Figs. 17 and 1 8, a method for manufacturing a device 100 for detecting and monitoring one or more local parameters within a solid structure 300 will be now described. Such a method comprises the steps of: producing a housing portion 1 51 , by using a building material formed of particles of micrometric or sub-micrometric dimensions, in which housing portion 1 51 a housing 150 is arranged; then, inserting an integrated detection module 1 of the device 100 into the housing 1 50; then, forming a filling portion 1 52, by using building material made of particles of micrometric or sub- micrometric dimensions, to produce a package 1 5 so arranged as to completely coat the integrated detection module 1 ; finally, securing the package 1 5 to support means 3 of the device 1 00, configured to further support electromagnetic means 2 of the device 100, and further configured so as to fix the device 1 00 to a supporting structure passing through the points to be monitored within the solid structure.

According to a further implementation example, illustrated in Fig. 18, the method comprises the further steps of producing a further portion of package, around a further portion of the device 100 with respect to the integrated detection module 1 , by injection of building material made of particles of micrometric or sub-micrometric dimensions into a mould 40.

In particular, after arranging the integrated detection module in the corresponding housing 1 50, the support 3 can be placed on the portion of the already formed package, and the package 15 is completed by further building material of the same type, in portions that are determined by the mould 40, so as to comprise any portion of the device, according to any of the already described embodiments of the device. In particular, inter alia, the housing 150, in which the integrated detection module 1 is located, is filled.

Recesses or holes may be located in the support 3, so as to connect the various portions of the package, thus making it, on the whole, more robust. The presence of such holes or recesses further allows the drainage of air, water, and water vapour that are present in the building material.

Advantageously, to avoid the formation of recesses and non-homogeneities within the package, the mould can be shaken to facilitate the escape of gases that are present in the mould itself.

In accordance with a further implementation example, the method provides for the further step of aligning the housing portion 151 and the filling portion 152 of the package 1 5, for example by simple mechanical guides.

According to a further embodiment of the method, it comprises (before the step of inserting the integrated detection module 1 into the housing 1 50) the further step of encapsulating the integrated detection module 1 in a pre-package made of building material.

It shall be noted that the object of the present invention is achieved by the package and the monitoring device described above, by virtue of their own characteristics.

In fact, the building material package of the present invention allows an accurate measurement of the local parameters to be monitored, while ensuring that the monitoring device of the present invention is simple, robust, and reliable, capable of resisting the pressures and temperatures present within a solid structure to be monitored, both in the construction step, and during its corresponding operative life, and further particularly resistant against the main degradation causes, such as those due for example to water and humidity.

The package, being made of a building material, is compatible with the structure. Meanwhile, the building material of the package, for example made at least partially of microsilica, is also compatible with the silicon sublayer of the chip on which the integrated detection module 1 of the device 1 00 is formed.

Furthermore, the shape of the package 15, according to the present invention, can be any shape, thus fitting a wide range of applications.

To the above-described embodiments of the package, the monitoring device, the monitoring system, and the manufacturing method, those of ordinary skill in the art, in order to meet contingent needs, will be able to make modifications, adaptations, and replacements of elements with other functionally equivalent ones, also in combination with the prior art, also generating hybrid implementations, without departing from the scope of the following claims.

Each of the characteristics described as belonging to a possible embodiment can be implemented independently from the other embodiments described.