AN ACQUISITION DEVICE, A METHOD OF FABRICATING IT, AND A METHOD OF MEASURING FORCE

• US 20170138804A1
• Filed: 03/27/2015
• Published: 05/18/2017
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: Consejo Superior de Investigaciones Científicas,, Ecole polytechnique, Institut francais des sciences et technologies des transports, de l'amenagement et des reseaux (IFSTTAR), Institut Francais Des Sciences Et Technologies Des Transports, De L'Amenagements Et Des Reseaux
• Original Assignee: Consejo Superior de Investigaciones Científicas,, Ecole polytechnique, Institut francais des sciences et technologies des transports, de l'amenagement et des reseaux (IFSTTAR)
• Inventors: LEBENTAL, Berengere, GHADDAD, Boutheina, GAUDEFROY, Vincent, RUIZ-HITZKY, Eduardo, ARANDA GALLEGO, Pilar, RUIZ GARCIA, Cristina, HENNINGS, Birger
• Granted Patent: US 10,989,612 B2
• Time in Patent Office: Days
• CPC Class Codes: G01G 19/021 having electrical weight-sensitive devices G01G19/04 - G01G19/07 take precedence
• CPC Class Codes: G01L 1/205 using distributed sensing elements

Abstract

An acquisition device (20) comprising a wall and a transducer (23) constituted by a body (24, 324) on which electrodes (25) are fastened spaced apart from one another.

An electrical impedance (R) of the transducer is variable as a function of deformation of the transducer.

When looking in a direction perpendicular to a surface (36) of the wall, at least two electrodes (25) of said plurality of electrodes are spaced apart from each other.

The transducer is incorporated under the surface (36) of the wall.

Claims

1. An acquisition device comprising a wall and a transducer, in which device the transducer is constituted by a body and a plurality of electrodes fastened to said body and spaced apart from one another;

the transducer is such that an electrical impedance determined from said plurality of electrodes is variable as a function of deformation to which the transducer is subjected; and

when looking in a direction perpendicular to a surface of the wall, at least two electrodes of said plurality of electrodes are spaced apart from each other;

wherein the transducer is incorporated under the surface of the wall.

2. An acquisition device according to claim 1, further comprising a transfer layer adhering to a face of the transducer and separating the transducer from the surface of the wall.

3. An acquisition device according to claim 2, wherein the transfer layer and the wall are made of the same material, in particular bituminous mix.

4. An acquisition device according to claim 3, wherein the transfer layer and the wall are formed integrally.

5. An acquisition device according to claim 1, arranged in such a manner that if a force is applied to the acquisition device in a direction perpendicular to the surface of the wall, the transducer deforms mainly in said direction perpendicular to the surface of the wall, and an impedance measured between the electrodes of said plurality of electrodes varies.

6. An acquisition device according to claim 1, arranged in such a manner that if a force is applied to the acquisition device in a direction perpendicular to the surface of the wall, the transducer deforms mainly in a plane substantially parallel to the wall, and an impedance measured between the electrodes of said plurality of electrodes varies.

7. An acquisition device according to claim 1, wherein the body of the transducer forms a thin layer, i.e. a layer of thickness less than one-tenth of at least one of the other two characteristic dimensions of said body.

8. An acquisition device according to claim 1, further comprising a bonding layer interposed between the body of the transducer and a surface neighboring the body of the transducer, the bonding layer adhering to the body of the transducer and to said neighboring surface.

9. An acquisition device according to claim 1, wherein the body of the transducer comprises a piezoresistive polymer or a mixture of a plurality of piezoresistive polymers, or a mixture of at least one polymer with conductive micro- and nano-particles or a mixture of bituminous mix or of bitumen with micro- and nano-particles.

10. An acquisition device according to claim 1, wherein the body of the transducer comprises a percolating array of micro- and/or nano-particles, said micro- and/or nano-particles comprising one or more particles from the following list:

a) carbon nanotubes, in particular in a random or an organized array;

b) self-assembled micro- or nano-particles; and

c) sheets of graphene, graphite, or optionally-reduced graphene oxide.

11. A tape comprising a plurality of acquisition devices according to claim 1, fastened on a strip.

12. A sensor including at least one acquisition device according to claim 1, and an impedance-determination system connected to electrodes of at least one transducer of said at least one acquisition device, and suitable for determining an impedance and/or an impedance variation of said at least one transducer.

13. A sensor according to claim 12, comprising a set of transducers arranged in an array, in particular so as to form a matrix, and further comprising means for identifying which transducers are activated or stressed at a given instant.

14. A display suitable for displaying variable information and including at least one acquisition device according to claim 1.

15. A force-measuring method comprising the following steps:

a) providing a transducer constituted by a body and by a plurality of electrodes fastened to said body and spaced apart from one another, the transducer being such that an electrical impedance determined from said plurality of electrodes is variable as a function of deformation to which the transducer is subjected;

b) applying a force to said transducer in a direction such that, when seen looking along said direction, at least two electrodes of said plurality of electrodes are spaced apart from each other;

c) measuring the variation of the impedance under the effect of the applied force; and

d) determining the applied force as a function of said impedance variation.

16. A method of fabricating an acquisition device comprising a wall and a transducer, the method comprising the following steps:

a) positioning a plurality of electrodes in contact with a body, the body and said electrodes being such that an electrical impedance determined from said plurality of electrodes is variable as a function of deformation to which the body associated with said plurality of electrodes is subjected;

the body and said plurality of electrodes thus form a transducer; and

b) forming the wall;

wherein steps a) and b) are performed in such a manner that the transducer is incorporated under a surface of the wall, and that, when seen looking along a direction perpendicular to said surface, at least two of said electrodes are spaced apart from each other.

17. A method of laying a roadway, the method comprising the following steps:

A) preparing a support surface; and

B) on said support surface, depositing at least one bituminous mix layer while incorporating therein at least one transducer, in such a manner that the roadway includes an acquisition device formed by a method according to claim 16.