Converter for converting a variation in energy to be recovered into a potential difference

Patent metadata

Field	Value
Publication number	US-2016276958-A1
Application number	US-201415031986-A
Country	US
Kind code	A1
Filing date	Oct 23, 2014
Priority date	Oct 25, 2013
Publication date	Sep 22, 2016
Grant date	—

Abstract

A converter including a first transducer that can lengthen inside at least a first deformation zone and simultaneously shrink inside at least a different second deformation zone. Inner faces of second and third electromechanical transducers are secured respectively, with no degree of freedom, substantially to the first and second deformation zones of the layer of the first transducer. The third transducer differs from the second transducer by the polarization of its layer of piezoelectric material in a different direction to polarization of the layer of piezoelectric material of the second transducer and/or by existence of a separation that mechanically and electrically insulates a first electrode of the third transducer from a first electrode of the second transducer located on a same side of the layer of piezoelectric material.

First claim

1 - 15 . (canceled)

16 : A converter of a variation in energy to be harvested into a potential difference, the converter comprising:
a first transducer including a layer extending substantially in a plane, as a reference plane, and behaving mechanically as a single block of material, the layer being configured to lengthen in an interior of at least one first zone of deformation of the reference plane and, simultaneously, to shrink in an interior of at least one second zone of deformation of the reference plane in response to a given variation in energy to be harvested, the second zone being distinct from the first zone; and electromechanical second and third transducers, each electromechanical transducer including:
a layer made of piezoelectric material extending substantially parallel to the reference plane and having exterior and interior faces extending parallel to the reference plane, an interior face being fixed with no degree of freedom to the layer of the first transducer to undergo a mechanical stress exerted by one of the zones of this layer; and
second electrodes made of electrically conductive material extending substantially parallel to the reference plane along at least one of the faces of the layer made of piezoelectric material of the second transducer to cause an excess of electrical charges to appear on one of these electrodes in response to the mechanical stress undergone by the layer made of piezoelectric material,
wherein the interior faces of the electromechanical second and third transducers are fixed with no degree of freedom substantially to the first and second zones of deformation of the layer of the first transducer, respectively, and the third transducer differs from the second transducer by a polarization of its layer made of piezoelectric material in a direction different from the polarization of the layer made of piezoelectric material of the second transducer and/or by existence of a separation mechanically and electrically insulating its first electrode from the first electrode of the second transducer, which electrode is located on a same side of the layer made of piezoelectric material.

17 : The converter as claimed in claim 16 , wherein:
the interior faces of the second and third transducers are fixed with no degree of freedom to a same face of the layer of the first transducer parallel to the reference plane; the polarizations of the layers made of piezoelectric material of the second and third transducers have opposite signs to each other so that the second and third transducers generate, at a same time, electrical charges of a same sign on their respective first electrodes in response to a given variation in the energy to be harvested; and the first electrodes are electrically connected to each other to form a common electrode on which the electrical charges generated simultaneously both by the second and third transducers accumulate.

18 : The converter as claimed in claim 17 , wherein the first electrodes comprise a layer made of electrically conductive material in a single block, which layer is deposited directly on the exterior faces of the layers made of piezoelectric material of the second and third transducers and covers most of the exterior faces of the two layers made of piezoelectric material to form an electrode common to the electromechanical second and third transducers.

19 : The converter as claimed in claim 17 , wherein the converter includes a fourth transducer including a layer extending substantially in a plane parallel to the reference plane and behaving mechanically as a single block of material, this layer configured to lengthen in the interior of at least one first zone of deformation parallel to the reference plane and, simultaneously, to shrink in the interior of at least one second zone of deformation parallel to the reference plane in response to a given variation in energy to be harvested, the second zone being distinct from the first zone and the first and second zones of deformation of the layer of the fourth transducer being directly opposite the first and second zones of deformation of the layer of the first transducer, respectively, and the exterior faces of the layers made of piezoelectric material of the second and third transducers are fixed with no degree of freedom essentially to the first and second zones of deformation of the layer of the fourth transducer, respectively.

20 : The converter as claimed in claim 16 , wherein the converter includes a partition that mechanically insulates the layers made of piezoelectric material of the second and third transducers, the width of this partition over most of its length located between the second and third transducers being smaller than the thickness of the layer made of piezoelectric material of these second and third transducers.

21 : The converter as claimed in claim 16 , wherein the piezoelectric material is PVDF (polyvinylidene fluoride) and the thickness of the layer made of piezoelectric material is smaller than 300 μm.

22 : The converter as claimed in claim 16 , wherein the layer of the first transducer has opposite top and bottom faces parallel to the reference plane and specimens of the second and third transducers are distributed over each of the two opposite faces of the layer of the first transducer symmetrically relative to a plane of symmetry parallel to the reference plane and located between the two opposite faces of the first transducer.

23 : The converter as claimed in claim 16 , wherein:
the interior faces of the second and third transducers are fixed with no degree of freedom to a same face of the layer of the first transducer parallel to the reference plane; the polarization directions of the layers made of piezoelectric material of the second and third transducers are parallel and of a same sign so that the second and third transducers generate at a same time electrical charges of opposite sign on their respective first electrodes in response to a given deformation of the first transducer, respectively; and the separation mechanically and electrically insulates the first electrodes from each other to generate between these first electrodes a larger potential difference than that existing between the interior and exterior faces of the piezoelectric layers of each of these electromechanical transducers.

24 : The converter as claimed in claim 16 , wherein:
the interior faces of the second and third transducers are fixed with no degree of freedom to a same face of the layer of the first transducer parallel to the reference plane; the polarizations of the layers made of piezoelectric material of the second and third transducers are parallel to the reference plane and shifted angularly one relative to the other so that the second and third transducers generate, at a same time, electrical charges of opposite sign on their respective first electrodes in response to a given variation in the energy to be harvested; and the separation mechanically and electrically insulates the first electrodes from each other to generate between these first electrodes a potential difference.

25 : The converter as claimed in claim 16 , wherein the layer of the first transducer is produced from magnetostrictive material, this layer made of magnetostrictive material configured to lengthen in the interior of the first zone of deformation and, simultaneously, to shorten in the interior of the second zone of deformation in response to a given variation in a magnetic field.

26 : The converter as claimed in claim 16 , wherein the layer of the first transducer is produced from shape-memory material, this layer made of shape-memory material configured to lengthen i

Assignees

• Commissariat L Energie Atomique Et Aux Energies Alternatives
• Inst Polytechnique Grenoble
• Commissariat Energie Atomique

Inventors

• Viala Bernard
• Delamare Jerome

Classifications

• H02N2/18 Primary

  producing electrical output from mechanical input, e.g. generators (for measurement devices G01) · CPC title

• H01L41/125

  Electricity · mapped topic

• H10N35/101

  with mechanical input and electrical output, e.g. generators, sensors · CPC title