BACKGROUND
[0001] The present disclosure generally relates to mattress assemblies, specifically to
temperature control mattress assemblies using thermoelectric fabric.
[0002] In order to maintain homeostasis the human body produces thermal energy during sleep
that is dissipated to the environment. This energy is transferred to the sleep surface
which stores the energy and subsequently increases in temperature. As temperatures
of the bed sleeping surface increase beyond the thermo-neutral zone, approximately
28 - 29 degrees Celsius (approximately 82 to 85 degrees Fahrenheit) the sleep environment
becomes uncomfortable and the sleeper often begins to perspire. Several mechanisms
for cooling the surface of a mattress have been developed, but these systems suffer
from a variety of limitations.
[0003] For example, fluid-based systems (both gas and liquid) have been employed to reduce
sleep surface temperature. These systems typically require a pump to circulate cooled
fluid through a mattress. These systems generate significant amounts of noise as they
pump fluid through manifolds or radiators in the mattress. Additionally, these systems
come at significant cost.
[0004] Alternatively, standard thermoelectric systems have been employed. These systems
typically use rigid components spaced about a mattress to utilize the Peltier effect
and transfer heat from the surface of the mattress. These systems are localized about
the components resulting in a surface with non-uniform temperature distribution. Additionally,
the rigid components limit their placement within the mattress assembly and can cause
discomfort for sleepers. In some existing designs, multiple thermoelectric components
are spaced about the interior of a mattress in order to cool a sleep surface. The
separation between components decreases effectivity, as the cooling mechanisms do
not treat the sleep surface uniformly. This generates hot and cold spots on the surface
of the mattress. An increase in the number of components would decrease mattress comfort
as the components are inflexible
US 2012/198616 A1 shows a mattress comprising a thermoelectric device comprising a plurality of thermoelectric
elements wherein the thermoelectric elements are woven in and out of holes in an insulating
panel wherein portions of the metal within the holes in the panel are mostly compacted
and portions outside the holes in the panel are mostly expanded, or pairs of thermoelectric
elements having metal therebetween are pushed through a hole from one side of an insulating
panel exposing a loop of expanded or expandable metal on the other side and retaining
the elements within the panel, mounted on top of the mattress, wherein (a) the mattress
is a spring mattress, and a portion of the conductor is exposed in the cavity containing
the springs and forced or natural convection of air is available in said cavity; or
(b) the mattress is an air mattress and the thermoelectric device is mounted on top
of the air mattress, and includes a thermal connection of the conductor on one side
of the device into the cavity containing the air and movement of the air is available
in said cavity; or (c) the mattress is a foam mattress and the thermoelectric device
is mounted on top of the thick foam mattress in which a portion of the conductor extends
into hollowed channels that provide natural or forced convection of air.
[0005] Accordingly, there remains a need for improved systems, devices, and methods of reducing
sleep surface temperature in mattress assemblies.
SUMMARY
[0006] A temperature control mattress is disclosed herein. The temperature control mattress
can include a body support having a proximal surface that is configured to support
a human body and a flexible thermoelectric fabric disposed along at least a portion
of the body support. The flexible thermoelectric fabric can be in thermal communication
with the proximal surface of the body support and such that the flexible thermoelectric
fabric is configured to cool the proximal surface of the body support.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] This disclosure will be more fully understood from the following detailed description
taken in conjunction with the accompanying drawings, in which:
Figure (FIG.) 1 is a side view of an expanded thermoelectric apparatus that can form
a flexible thermoelectric fabric;
FIG. 2 is an exemplary thermoelectric apparatus;
FIG. 3 is a side view of an exemplary flexible thermoelectric fabric;
FIG. 4 is a perspective cut-away view of an exemplary mattress assembly that includes
a flexible thermoelectric fabric;
FIG. 5 is a cut-away view of an exemplary mattress assembly that includes a flexible
thermoelectric fabric;
FIG. 6 is a perspective view of an exemplary flexible thermoelectric fabric;
FIG. 7 is a diagram of a Peltier effect with respect to a flexible thermoelectric
fabric; and
FIG. 8 is a diagram of a Seebeck effect with respect to a flexible thermoelectric
fabric.
DETAILED DESCRIPTION
[0008] Certain exemplary aspects will now be described to provide an overall understanding
of the principles of the structure, function, manufacture, and use of the devices,
systems, methods, and/or kits disclosed herein. One or more examples of these aspects
are illustrated in the accompanying drawings. Those skilled in the art will understand
that the devices, systems, methods, and/or kits disclosed herein and illustrated in
the accompanying drawings are non-limiting and exemplary in nature and that the scope
of the present invention is defined solely by the claims. The features illustrated
or described in connection with any one aspect described may be combined with the
features of other aspects. Such modification and variations are intended to be included
within the scope of the present disclosure.
[0009] Further in the present disclosure, like-numbered components generally have similar
features, and thus each feature of each like-numbered component is not necessarily
fully elaborated upon. Additionally, to the extent that linear or circular dimensions
are used in the description of the disclosed systems, devices, and methods, such dimensions
are not intended to limit the types of shapes that can be used in conjunction with
such systems, devices, and methods. A person skilled in the art will recognize that
an equivalent to such linear and circular dimensions can be determined for any geometric
shape. Sizes and shapes of the systems and devices, and the components thereof, can
depend at least on the size and shape of the components with which the systems and
devices will be used, and the methods and procedures in which the systems and devices
will be used.
[0010] Flexible thermoelectric fabrics have been developed for use in various applications.
For example and without limitation, thermoelectric fabrics are disclosed in
U.S. Publication No. 2013/0312806, which is titled "Thermoelectric Apparatus and Applications Thereof". These flexible
thermoelectric fabrics can employ a layered p-n junction material to generate temperature
gradients from electricity. Modules of the material may be arranged in series, parallel
or a combination in order to achieve the desired temperature distribution. The thermoelectric
fabric remains flexible due to its polymeric construction. This allows for retained
comfort when placing the layers closer to the surface of the mattress where the body
is generating heat. Thermoelectric fabrics can also cover an entire sleep surface
if needed. This can decrease the positional requirements of the sleeper allowing them
to move freely in the mattress while still experiencing uniform temperature distribution.
[0011] Flexible, polymer-based thermoelectric fabrics can be constructed through the lamination
of doped p- and n- junction polymers separated by an insulating material. These laminated
modules can be stacked and arranged in series, parallel or a combination in order
to achieve the desired temperature distribution. Polymer based thermoelectric fabrics
can be placed nearer the surface of a mattress to increase efficiency of the cooling
or heating process.
[0012] As is explained in greater detail in
U.S. Publication No. 2013/0312806, FIG. 1 illustrates an expanded side view of a thermoelectric apparatus that forms
example flexible thermoelectric fabrics. The thermoelectric apparatus illustrated
in FIG. 1 comprises two p-type layers 1 coupled to an n-type layer 2 in an alternating
fashion. The alternating coupling of p-type 1 and n-type 2 layers provides the thermoelectric
apparatus a z-type configuration having p-n junctions 4 on opposite sides of the apparatus.
Insulating layers 3 are disposed between interfaces of the p-type layers 1 and the
n-type layer 2 as the p-type 1 and n-type 2 layers are in a stacked configuration.
As shown, the thermoelectric apparatus provided in FIG. 1 is in an expanded state
to facilitate illustration and understanding of the various components of the apparatus.
In some aspects, however, the thermoelectric apparatus is not in an expanded state
such that the insulating layers 3 are in contact with a p-type layer 1 and an n-type
layer 2.
[0013] FIG. 1 additionally illustrates the current flow through the thermoelectric apparatus
induced by exposing one side of the apparatus to a heat source. Electrical contacts
X are provided to the thermoelectric apparatus for application of the thermally generated
current to an external load.
[0014] Again, as is explained in greater detail in
U.S. Publication No. 2013/0312806, FIG. 2 illustrates an exemplary thermoelectric apparatus 200, wherein the p-type
layers 201 and the n-type layers 202 are in a stacked configuration. The p-type layers
201 and the n-type layers 202 can be separated by insulating layers 207 in the stacked
configuration. The thermoelectric apparatus 200 can be connected to an external load
by electrical contacts 204, 205.
[0015] FIG. 3 illustrates an exemplary flexible thermoelectric fabric 300. The flexible
thermoelectric fabric 300 can comprise a thermoelectric apparatus as described above
with respect to FIGS. 1-2 such that the apparatus forms a fabric that is capable of
bending easily without breaking the circuits. As such, in some aspects, the flexible
thermoelectric fabric can comprise at least one p-type layer coupled to at least one
n-type layer to provide a p-n junction, and an insulating layer at least partially
disposed between the p-type layer and the n-type layer, the p-type layer comprising
a plurality of carbon nanoparticles and the n-type layer comprising a plurality of
n-doped carbon nanoparticles. In some aspects, carbon nanoparticles of the p-type
layer are p-doped and carbon nanoparticles of the n-type layer are n-doped. In some
aspects, a p-type layer of a flexible thermoelectric fabric or apparatus can further
comprise a polymer matrix in which the carbon nanoparticles are disposed. In some
aspects, an n-type layer further comprises a polymer matrix in which the n-doped carbon
nanoparticles are disposed. In some aspects, p-type layers and n-type layers of a
flexible thermoelectric fabric or apparatus described herein are in a stacked configuration.
[0016] In some aspects, carbon nanoparticles of a p-type layer comprise fullerenes, carbon
nanotubes, or mixtures thereof. In some aspects, carbon nanotubes can comprise single-walled
carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT), as well as p-doped
single-walled carbon nanotubes, p-doped multi-walled carbon nanotubes or mixtures
thereof. N-doped carbon nanoparticles can comprise fullerenes, carbon nanotubes, or
mixtures thereof. In some aspects, n-doped carbon nanotubes can also comprise single-walled
carbon nanotubes, muiti-walled carbon nanotubes or mixtures thereof.
[0017] In some aspects, a p-type layer and/or n-type layer can further comprise a polymeric
matrix in which the carbon nanoparticles are disposed. Any polymeric material not
inconsistent with the objectives of the present invention can be used in the production
of a polymeric matrix. In some aspects, a polymeric matrix comprises a fluoropolymer
including, but not limited to, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF),
polytetrafluoroethylene (PTFE), or mixtures or copolymers thereof. In some aspects,
a polymer matrix comprises polyacrylic acid (PAA), polymethacrylate (PMA), polymethylmethacrylate
(PMMA) or mixtures or copolymers thereof. In some aspects, a polymer matrix comprises
a polyolefin including, but not limited to polyethylene, polypropylene, polybutylene
or mixtures or copolymers thereof. A polymeric matrix can also comprise one or more
conjugated polymers and can comprise one or more semiconducting polymers.
[0018] As a person of ordinary skill will understand, the "Seebeck coefficient" of a material
is a measure of the magnitude of an induced thermoelectric voltage in response to
a temperature difference across that material. A p-type layer, in some aspects, can
have a Seebeck coefficient of at least about 3 µV/K at a temperature of 290° K. In
some aspects, a p-type layer has a Seebeck coefficient of at least about 5 µV/K. at
a temperature of 290° K. In some aspects, a p-type layer has a Seebeck coefficient
of at least about 10 µV/K at a temperature of 290° K. In some aspects, a p-type layer
has a Seebeck coefficient of at least about 15 µV/K or at least about 20 µV/K at a
temperature of 290° K. In some aspects, a p-type layer has a Seebeck coefficient of
at least about 30 µV/K at a temperature of 290° K. A p-type layer, in some aspects,
has a Seebeck coefficient ranging from about 3 µV/K to about 35 µV/K at a temperature
of 290° K. A p-type layer, in some aspects, has a Seebeck coefficient ranging from
about 5 µV/K to about 35 µV/K at a temperature of 290° K. In some aspects, a p-type
layer has Seebeck coefficient ranging from about 10 µV/K to about 30 µV/K at a temperature
of 290° K. As described herein, in some aspects, the Seebeck coefficient of a p-type
layer can be varied according to carbon nanoparticle identity and loading. In some
aspects, for example, the Seebeck coefficient of a p-type layer is inversely proportional
to the single-walled carbon nanotube loading of the p-type layer.
[0019] Similarly, an n-type layer can have a Seebeck coefficient of at least about -3 µV/K
at a temperature of 290° K. In some aspects, an n-type layer has a Seebeck coefficient
at least about -5 µV/K at a temperature of 290° K. In some aspects, an n-type layer
has a Seebeck coefficient at least about -10 µV/K at a temperature of 290° K. In some
aspects, an n-type layer has a Seebeck coefficient of at least about -15 µV/K or at
least about -20 µV/K at a temperature of 290° K. In some aspects, an n-type layer
has a Seebeck coefficient of at least about -30 µV/K at a temperature of 290° K. An
n-type layer, in some aspects, has a Seebeck coefficient ranging from about -3 µV/K
to about -35 µV/K at a temperature of 290° K. In some aspects, an n-type layer has
Seebeck coefficient ranging from about 5 µV/K to about -35 µV/K at a temperature of
290° K. In some aspects, an n-type layer has Seebeck coefficient ranging from about
-10 µV/K to about -30 µV/K at a temperature of 290° K. In some aspects, the Seebeck
coefficient of an n-type layer can be varied according to n-doped carbon nanoparticle
identity and loading. In some aspects, for example, the Seebeck coefficient of an
n-type layer is inversely proportional to the carbon nanoparticle loading of the n-type
layer.
[0020] As described herein and in
U.S. Publication No. 2013/0312806, in some aspects the flexible thermoelectric fabric can include an insulating layer.
An insulating layer can comprise one or more polymeric materials. Any polymeric material
not inconsistent with the objectives of the present invention can be used in the production
of an insulating layer. In some aspects, an insulating layer comprises polyacrylic
acid (PAA), polymethacrylate (PMA), polymethylmethacrylate (PMMA) or mixtures or copolymers
thereof. In some aspects, an insulating layer comprises a polyolefin including, but
not limited to polyethylene, polypropylene, polybutylene or mixtures or copolymers
thereof. In some aspects, an insulating layer comprises PVDF. An insulating layer
can have any desired thickness not inconsistent with the objectives of the present
invention. In some aspects, an insulating layer has a thickness of at least about
50 nm. In some aspects, an insulating layer has a thickness ranging from about 5 nm
to about 50 µm Additionally, an insulating layer can have any desired length not inconsistent
with the objectives of the present invention. In some aspects, an insulating layer
has a length substantially consistent with the lengths of the p-type and n-type layers
between which the insulating layer is disposed. That is, in some aspects, an insulating
layer, p-type layer, and/or n-type layer can have a length of at least about 1 µm.
In some aspects, an insulating layer, p-type layer, and/or n-type layer can have a
length ranging from about 1 µm to about 500 mm.
[0021] In use, the flexible thermoelectric fabric can be incorporated into a mattress assembly.
In so doing, the mattress assembly can be configured to be a temperature control mattress
and, additionally or alternatively, can be configured to produce an electric charge.
FIG. 4 illustrates an example mattress assembly 400 having a body support 402. The
body support 402 has a proximal surface 404 that can support a body 406. The body
406, as shown, can be a human body and the body support 402 can be configured to support
the body in a prone, supine, semi-supine, sitting, or any other position so long as
the body support 402 supports some portion of the body.
[0022] FIG. 5 illustrates an example mattress assembly 500. As shown, the mattress assembly
500 can have an inner support 502 and a body support surface 504. In some aspects,
the inner support 502 can be any of a spring, foam, air, or any other core support
structure known in the art. The body support surface 504 can, as shown, include a
variety of layers 506, 508, 510, 512, 514. The layers can be formed of any support
material including foams, gels, fabrics, down feathers, or any other known support
material. Additionally, the layers 506, 508, 510, 512, 514 can be configured to allow
heat to transfer from the proximal surface or proximal most layer 506 to the distal
most layer 514. As such, a flexible thermoelectric fabric can be disposed between
any of layers 506, 508, 510, 512, 514. Alternatively and/or additionally, any of the
layers 506, 508, 510, 512, 514 can be formed of an example flexible thermoelectric
fabric in accordance with the disclosures made herein. For example, layer 506 can
be a decorative quilt mattress topper. In some aspects, the quilt topper 506 can be
formed of a flexible thermoelectric fabric.
[0023] As shown in FIG. 6, the flexible thermoelectric fabric 608 can be formed of stacked
p-layers, n-layers, and insulation layers, as is described above. As such, the flexible
thermoelectric fabric 608 can be configured to utilize the Peltier effect and/or the
Seebeck effect. As used herein and as a person of ordinary skill will understand,
the "Peltier effect" means the presence of heating or cooling at an electrified junction
of two different conductors. Further, as a person of ordinary skill will understand,
the "Seebeck effect" means an induced thermoelectric voltage in response to a temperature
differential across a material.
[0024] FIG. 7 illustrates an exemplary diagram of the Peltier effect, which can result in
cooling of the body support surface when the flexible thermoelectric fabric is disposed
such that it is in thermal communication with the proximal surface of the body support.
In this manner, the top-most layer 702 of the fabric is cooled as charge moves through
the player 704 and n-layers 706 accordingly. As such, heat is dissipated along a bottom-most
surface 708 of the fabric as the p-layer(s) and n-layer(s) are connected by a circuit
710.
[0025] Fig. 8 illustrates a schematic diagram of the Seebeck effect, which can result in
the generation of an electrical voltage when the flexible fabric is heated at the
proximal surface of the body support, such as when a human lays on the body support
and transfers its body heat into the proximal surface of the body support. As shown,
the top-most surface 802 of the fabric is exposed to a heat source-
i.e., a sleeper's body heat-and the bottom-most surface 808 is at a temperature that
is cooler than the top-most layer 802. Voltage is generated by the system when the
p-layers 804 are connected to the n-layers 806 with a load resistor 810.
[0026] Thus, in some aspects, either to maximize temperature regulation of the sleeping
surface (
i.e., the proximal surface of the body support) or to maximize a current generated by the
flexible fabric, the fabric can be disposed along an entire proximal surface of a
mattress. As was described above, for example, a mattress topper can be formed entirely
of flexible thermoelectric fabric. Alternatively, the fabric can be strategically
located along portions of the fabric so as to maximize thermal communication between
the proximal surface and the fabric. That is, the fabric can be placed in any manner
that is consistent with absorbing a desired and/or optimal amount of body heat from
a body. Additionally, the flexible nature of the example thermoelectric fabrics provide
various advantages as described herein. For example, they are less costly to produce,
more comfortable, more easily integrated and would provide more well distributed functionality
on a large surface such as a mattress. The above disclosure solves positional and
comfort issues by allowing for uniform thermal control decreasing hot spots or cold
spots. This in turn also allows the sleeper to move freely without sensing changes
in the cooling/heating system efficiency and furthermore, allows for the thermoelectric
system to be near the surface of the mattress for greater efficiency.
[0027] Further, various modifications may be made of the invention without departing from
the scope thereof, and it is desired, therefore, that only such limitations shall
be placed thereon as are set forth in the appended claims.
1. A temperature control mattress (500), comprising:
a body support (502) having a proximal surface (504) that is configured to support
a human body;
a flexible thermoelectric fabric (300) disposed along at least a portion of the body
support (502) such that the flexible thermoelectric fabric is in thermal communication
with the proximal surface (504) of the body support (502) and such that the flexible
thermoelectric fabric (300) is configured to cool the proximal surface (504) of the
body support (502), wherein the flexible thermoelectric fabric (300) comprises a plurality
of carbon nanotubes, and wherein a portion of the carbon nanotubes are single-walled
carbon nanotubes.
2. The mattress of claim 1, wherein the flexible thermoelectric fabric (300) is disposed
along the entire proximal surface (504) of the body support (502).
3. The mattress of claim 1, wherein the plurality of carbon nanotubes form a plurality
of p-type layers (201) coupled to a plurality of n-type layers (202) to provide a
plurality of p-n junctions.
4. The mattress of claim 1, wherein the flexible thermoelectric fabric (300) further
comprises at least one insulating layer (207).
5. The mattress of claim 1, wherein the flexible thermoelectric fabric is disposed between
layers (506, 508, 510, 512, 514) forming the body support (502).
6. The mattress of claim 3, wherein the plurality of p-type layers (201) have a Seebeck
coefficient of at least about 3 µV/K at 290° K.
7. The mattress of claim 3, wherein the plurality of n-type layers (202) have a Seebeck
coefficient of at least about -3 µV/K at 290° K.
8. The mattress of claim 3, wherein the plurality of carbon nanotubes are disposed in
a polymer matrix.
1. Temperaturregelungsmatratze (500), aufweisend:
eine Körperstütze (502) mit einer proximalen Oberfläche (504), die zum Stützen eines
menschlichen Körpers ausgebildet ist;
ein flexibles thermoelektrisches Textilmaterial (300), das entlang mindestens eines
Bereichs der Körperstütze (502) derart angeordnet ist, dass sich das flexible thermoelektrische
Textilmaterial mit der proximalen Oberfläche (504) der Körperstütze (502) in thermischer
Verbindung befindet, sowie derart, dass das flexible thermoelektrische Textilmaterial
(300) zum Kühlen der proximalen Oberfläche (504) der Körperstütze (502) ausgebildet
ist, wobei das flexible thermoelektrische Textilmaterial (300) eine Mehrzahl von Kohlenstoff-Nanoröhrchen
aufweist und wobei ein Teil der Kohlenstoff-Nanoröhrchen einwandige Kohlenstoff-Nanoröhrchen
sind.
2. Matratze nach Anspruch 1,
wobei das flexible thermoelektrische Textilmaterial (300) entlang der gesamten proximalen
Oberfläche (504) der Körperstütze (502) angeordnet ist.
3. Matratze nach Anspruch 1,
wobei die Mehrzahl von Kohlenstoff-Nanoröhrchen eine Mehrzahl von p-leitenden Schichten
(201) bildet, die mit einer Mehrzahl von n-leitenden Schichten (202) gekoppelt sind,
um eine Mehrzahl von p-n-Übergängen bereitzustellen.
4. Matratze nach Anspruch 1,
wobei das flexible thermoelektrische Textilmaterial (300) ferner mindestens eine Isolierschicht
(207) aufweist.
5. Matratze nach Anspruch 1,
wobei das flexible thermoelektrische Textilmaterial zwischen Schichten (506, 508,
510, 512, 514) angeordnet ist, die die Körperstütze (502) bilden.
6. Matratze nach Anspruch 3,
wobei die Mehrzahl von p-leitenden Schichten (201) einen Seebeck-Koeffizienten von
mindestens etwa 3 µV/K bei 290° K aufweist.
7. Matratze nach Anspruch 3,
wobei die Mehrzahl von n-leitenden Schichten (202) einen Seebeck-Koeffizienten von
mindestens etwa - 3 µV/K bei 290° K aufweist.
8. Matratze nach Anspruch 3,
wobei die Mehrzahl von Kohlenstoff-Nanoröhrchen in einer Polymermatrix angeordnet
ist.
1. Matelas à régulation de température (500), comprenant :
un support de corps (502) présentant une surface proximale (504), laquelle est configurée
pour supporter un corps humain, et
un tissu thermoélectrique flexible (300) disposé le long d'au moins une portion du
support de corps (502) de telle sorte que le tissu thermoélectrique flexible présente
une communication thermique avec la surface proximale (504) du support de corps (502),
et que le tissu thermoélectrique flexible (300) est configuré pour refroidir la surface
proximale (504) du support de corps (502), dans lequel le tissu thermoélectrique flexible
(300) comprend une pluralité de nanotubes de carbone, et dans lequel une portion des
nanotubes de carbone sont des nanotubes de carbone à paroi simple.
2. Matelas selon la revendication 1, dans lequel le tissu thermoélectrique flexible (300)
est disposé le long de toute la surface proximale (504) du support de corps (502).
3. Matelas selon la revendication 1, dans lequel la pluralité de nanotubes de carbone
forment une pluralité de couches de type p (201) couplées à une pluralité de couches
de type n (202) afin de fournir une pluralité de jonctions p-n.
4. Matelas selon la revendication 1, dans lequel le tissu thermoélectrique flexible (300)
comprend en outre au moins une couche isolante (207).
5. Matelas selon la revendication 1, dans lequel le tissu thermoélectrique flexible est
disposé entre des couches (506, 508, 510, 512, 514) formant le support de corps (502).
6. Matelas selon la revendication 3, dans lequel la pluralité de couches de type p (201)
présentent un coefficient de Seebeck d'au moins environ 3 µV/K à 290 ° K.
7. Matelas selon la revendication 3, dans lequel la pluralité de couches de type n (202)
présentent un coefficient de Seebeck d'au moins environ -3 µV/K à 290 ° K.
8. Matelas selon la revendication 3, dans lequel la pluralité de nanotubes de carbone
sont disposés dans une matrice polymère.