U.S. patent application number 11/608378 was filed with the patent office on 2008-06-12 for thermal management system for embedded environment and method for making same.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Mehmet Arik, William Henry Lueckenbach, Charles Erklin Seeley, David Shannon Slaton, Yogen Vishwas Utturkar, Charles Franklin Wolfe.
Application Number | 20080137289 11/608378 |
Document ID | / |
Family ID | 39111420 |
Filed Date | 2008-06-12 |
United States Patent
Application |
20080137289 |
Kind Code |
A1 |
Arik; Mehmet ; et
al. |
June 12, 2008 |
THERMAL MANAGEMENT SYSTEM FOR EMBEDDED ENVIRONMENT AND METHOD FOR
MAKING SAME
Abstract
A thermal management system for an embedded environment is
described. The thermal management system includes a pleumo-jet that
has at least one wall defining a chamber, at least one
piezoelectric device on the at least one wall, and a compliant
material within the at least one wall and encompassing the chamber.
The compliant material has at least one opening providing fluid
communication between said chamber and the embedded environment. A
cooling system is also described. A method for making a pleumo-jet
is also described.
Inventors: |
Arik; Mehmet; (Niskayuna,
NY) ; Wolfe; Charles Franklin; (Albany, NY) ;
Utturkar; Yogen Vishwas; (Latham, NY) ; Seeley;
Charles Erklin; (Niskayuna, NY) ; Slaton; David
Shannon; (Huntsville, AL) ; Lueckenbach; William
Henry; (Charlottesville, VA) |
Correspondence
Address: |
GENERAL ELECTRIC COMPANY;GLOBAL RESEARCH
PATENT DOCKET RM. BLDG. K1-4A59
NISKAYUNA
NY
12309
US
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
39111420 |
Appl. No.: |
11/608378 |
Filed: |
December 8, 2006 |
Current U.S.
Class: |
361/689 |
Current CPC
Class: |
Y10T 29/49826 20150115;
Y10S 165/908 20130101; Y10T 29/4935 20150115; G06F 1/20
20130101 |
Class at
Publication: |
361/689 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1. A thermal management system for a heated environment,
comprising: a pleumo-jet, comprising: at least one wall defining a
chamber; at least one active material on said at least one wall;
and a compliant material within said at least one wall and
encompassing said chamber, said compliant material having at least
one opening facilitating fluid communication between said chamber
and the heated environment.
2. The thermal management system of claim 1, wherein said compliant
material comprises an elastomeric material.
3. The thermal management system of claim 1, comprising an
electrical circuit to provide an electrical current to said
pleumo-jet.
4. The thermal management system of claim 3, wherein said
electrical current is one exhibiting lowered harmonics.
5. The thermal management system of claim 4, wherein said
electrical current omprises a sine wave.
6. The thermal management system of claim 1, wherein the heated
environment includes single board computers, programmable logic
controllers (PLCs), operator interface computers, laptop computers,
cell phones, personal digital assistants (PDAs), and personal
pocket computers.
7. The thermal management system of claim 1, wherein the heated
environment comprises at least one heated body.
8. The thermal management system of claim 7, wherein said at least
one opening is positioned to eject an ambient fluid directly on
said at least one heated body.
9. The thermal management system of claim 8, wherein said at least
one opening is at an angle transverse to an upper surface of the at
least one heated body.
10. The thermal management system of claim 1, wherein said
elastomeric material comprises a plurality of openings facilitating
fluid communication between said chamber and the heated
environment.
11. The thermal management system of claim 10, wherein said at
least one wall has a circular profile.
12. The thermal management system of claim 10, wherein said at
least one wall has a rectangular profile.
13. The thermal management system of claim 1, comprising: a base
upon which said pleumo-jet is positioned; and a plurality of fins
surrounding said pleumo-jet.
14. The thermal management system of claim 13, comprising a
plurality of pleumo-jets positioned on said base in a stacked
arrangement.
15. The thermal management system of claim 1, wherein said
pleumo-jet comprises a pair of walls sandwiching said elastomeric
material, each of said walls having said at least one piezoelectric
device.
16. A pleumo-jet, comprising: a first flexible structure; a second
flexible structure; at least one active material on at least one of
said first and second flexible structures; and a compliant material
positioned between said first and second flexible structures and
defining a chamber, wherein said compliant material comprises at
least one orifice for facilitating fluid communication between said
chamber and an ambient environment.
17. The pleumo-jet of claim 16, comprising an electrical circuit to
provide an electrical current to the at least one active
material.
18. The pleumo-jet of claim 16, wherein said compliant material
comprises an elastomeric material.
19. The pleumo-jet of claim 16, wherein said apparatus is no larger
than meso-scale sized.
20. The pleumo-jet of claim 16, wherein said at least one active
material comprises a piezoceramic material.
21. The pleumo-jet of claim 16, wherein said at least one active
material is positioned on both of said first and second flexible
structures.
22. A cooling system for a heated environment, comprising: a
substrate having one free end and one anchored end; at least one
piezoelectric device positioned on said substrate; and an
electrical circuit to provide an electrical current to the at least
one piezoelectric device.
23. The cooling system of claim 22, wherein the heated environment
includes single board computers, programmable logic controllers
(PLCs), operator interface computers, laptop computers, cell
phones, personal digital assistants (PDAs), and personal pocket
computers.
24. The cooling system of claim 22, wherein said substrate is no
larger than meso-scale sized.
25. A method for making a pleumo-jet, comprising: providing a pair
of flexible flexible structures, at least one of the structures
having an attached active material; attaching a compliant material
between the pair of flexible structures, said elastomeric material
having at least one orifice; and adding electrical contacts to the
pair of flexible structures.
26. The method of claim 25, wherein said providing comprises
providing attached active material for each of the pair of flexible
flexible structures.
27. The method of claim 25, wherein said attaching comprises
attaching an elastomeric material between the pair of flexible
structures.
28. The method of claim 25, wherein said attaching comprises:
dispensing the compliant material as a semi-liquid silicone-based
material; contacting the semi-liquid silicon-based material with
one of the flexible structures; and placing the other of the
flexible structures in contact with the semi-liquid silicone-based
material.
29. The method of claim 25, wherein said attaching comprises:
forming the compliant material from a pre-made sheet of
silicone-based material; and bonding the compliant material to the
pair of flexible structures.
Description
BACKGROUND
[0001] The invention relates generally to thermal management
systems, and more particularly to thermal management systems for
use in embedded environments.
[0002] Environments having embedded electronic systems, hereinafter
embedded environments or heated environments, offer challenges for
thermal management. Such systems produce waste heat as a part of
their normal operation, heat that must be removed for proper
performance and reliability of the embedded electronics. The design
of thermal management systems to provide cooling for embedded
electronics is a formidable challenge due to space limitations.
Examples of embedded electronic systems include single board
computers, programmable logic controllers (PLCs), operator
interface computers, laptop computers, cell phones, personal
digital assistants (PDAs), personal pocket computers, and other
small electronic devices, there is a limited amount of available
space for thermal management systems. It has been known to use
passive cooled heat sinks or forced air-cooling as thermal
management systems to assist in the removal of heat from electronic
components. Further, it has been known that conducting the heat
generated by electronic components to a printed circuit board, on
which they are mounted, thereby providing a migration of the heat
from a smaller area to a larger area.
SUMMARY
[0003] The invention includes embodiments that relate to a thermal
management system for a heated environment that includes a
pleumo-jet. The pleumo-jet includes at least one wall defining a
chamber, at least one active material on the at least one wall, and
a compliant material within the at least one wall and encompassing
the chamber. The compliant material has at least one opening
facilitating fluid communication between the chamber and the heated
environment.
[0004] The invention includes embodiments that relate to a
pleumo-jet that includes a first flexible structure, a second
flexible structure, at least one active material on at least one of
the first and second flexible structures, and a compliant material
positioned between the first and second flexible structures and
defining a chamber. The compliant material includes at least one
orifice for facilitating fluid communication between the chamber
and an ambient environment.
[0005] The invention includes embodiments that relate to a cooling
system for a heated environment. The cooling system includes a
substrate having one free end and one anchored end, at least one
piezoelectric device positioned on the substrate, and an electrical
circuit to provide an electrical current to the at least one
piezoelectric device.
[0006] The invention includes embodiments that relate to a method
for making a pleumo-jet. The method includes providing a pair of
flexible structures, at least one of the structures having an
attached active material, attaching a compliant material between
the pair of flexible structures, the elastomeric material having at
least one orifice, and adding electrical contacts to the pair of
flexible structures.
[0007] These and other advantages and features will be more readily
understood from the following detailed description of preferred
embodiments of the invention that is provided in connection with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional side view of a thermal
management system utilizing a pleumo-jet constructed in accordance
with an embodiment of the invention.
[0009] FIG. 2 is a cross-sectional side view showing the thermal
management system of FIG. 1 with the pleumo-jet in a different
position.
[0010] FIG. 3 is a top view of a thermal management system
constructed in accordance with an embodiment of the invention.
[0011] FIG. 4 is a cross-sectional side view of the thermal
management system of FIG. 3 taken along line IV-IV.
[0012] FIG. 5 is a top view of a pleumo-jet constructed in
accordance with an embodiment of the invention.
[0013] FIG. 6 is a top view of a pleumo-jet constructed in
accordance with an embodiment of the invention.
[0014] FIG.7 is a side view of the pleumo-jet of FIG. 6.
[0015] FIG. 8 is a schematic view a thermal management system
utilizing a piezoelectrically driven flexible cooling apparatus
constructed in accordance with an embodiment of the invention.
[0016] FIG. 9 is a schematic view showing the thermal management
system of FIG. 8 with the piezoelectrically driven flexible cooling
apparatus in a different position.
[0017] FIG. 10 illustrates process steps for forming a pleumo-jet
in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[0018] Referring to FIGS. 1 and 2, there is shown a thermal
management system 10 that includes a pleumo-jet 12 illustrated in
cross-section and placed in proximity to a printed circuit board
assembly (PCA) 30 having a plurality of electronic components to be
cooled 32.sub.a-d. While a PCA 30 is depicted with reference to an
embodiment of the invention, it should be appreciated that the
thermal management system 10 may be utilized in any suitable
embedded environment and its depiction with reference to the PCA 30
is merely for convenience in description. The PCA 30 may be used in
heated environments in any number of small electronic devices, such
as, for example, single board computers, programmable logic
controllers (PLCs), laptop computers, cell phones, personal digital
assistants (PDAs), personal pocket computers, to name a few. The
pleumo-jet 12 is sized appropriately for its use, and generally is
in the meso-scale or micro-scale.
[0019] The pleumo-jet 12 is positioned such that a pulsating fluid
stream of ambient air can be generated from the apparatus 12 and
directed at the electronic components to be cooled 32.sub.a-d. As
shown, in FIG. 1, a fluid stream of ambient air, or other fluid, is
directed along direction A toward the electronic component to be
cooled 32.sub.b. Alternatively, the pleumo-jet 12 may be positioned
to direct a fluid stream of ambient air along direction B toward
the electronic component to be cooled 32.sub.b (FIG. 2).
[0020] The pleumo-jet 12 includes a first structure or wall 14 and
a second structure or wall 16. The walls 14, 16 are formed of a
flexible material, such as, for example, metal, foil, plastic, or
polymer composite material. A compliant material 18 is positioned
between the pair of walls 14, 16, and the combination of the walls
14, 16 and the compliant material 18 define a chamber 20. At least
one orifice 22 provides a channel between the chamber 20 and the
environment outside the apparatus 12. Although a pair of opposing
walls 14, 16 are depicted, it should be appreciated that instead of
two walls, a single wall (wrapping around to form a cylinder) along
with the compliant material 18 may form a pleumo-jet, such as the
pleumo-jet 12.
[0021] Positioned on at least one of the walls 14, 16 is an active
material, such as, for example, a piezoelectric material. As shown,
active materials 24 and 26 are positioned, respectively, on walls
14 and 16. A suitable active material is one which is capable of
creating stress resulting from an electrical stimulus. Examples of
suitable active material include piezoelectric material,
magnetostrictive material (magnetic fields from coils
attract/oppose one another), shape-memory alloy, and motor
imbalance (motor with a mass imbalance creates oscillatory motion).
Within the subset of piezoelectric materials, suitable active
materials include bimorph piezoelectric configurations, where two
piezo layers are energized out of phase to produce bending; thunder
configurations, where one piezo layer is disposed on a pre-stressed
stainless steel shim; buzzer element configurations, where one
piezo layer is disposed on a brass shim; and MFC configurations,
where a piezo fiber composite on a flexible circuit is bonded to a
shim.
[0022] The active material 24, 26 may incorporate a ceramic
material. Electrical circuitry (schematically depicted in FIG. 8)
is attached to the pleumo-jet 12 to provide an electrical current
to one or both of the active material 24, 26. The current may be
provided as a sine wave, a square wave, a triangular wave, or any
other suitable waveform, and it should be appreciated that the
current is not to be limited to any specific wave form.
Specifically, it has been found that currents having lower
harmonics, such as, for example, a sine wave may be used to provide
a quieter pleumo-jet 12.
[0023] FIGS. 3 and 4 illustrate a thermal management system 110 in
accordance with another embodiment of the invention. The thermal
management system 110 includes a pleumo-jet system 111, which has a
plurality of pleumo-jets in a stacked arrangement. As shown, the
pleumo-jet system 111 includes pleumo-jets 112.sub.a, 112.sub.b,
and 112.sub.c in a stacked arrangement. The pleumo-jet 112.sub.c is
positioned over a base 129 and supported in that location with one
or more supports 127. The pleumo-jets 112.sub.a, 112.sub.b, and
112.sub.c have a similar construction to the pleumo-jet 12 (FIGS.
1, 2), with the optional exception of the orifices. Specifically,
each of the pleumo-jets 112.sub.a, 112.sub.b, and 112.sub.c
includes flexible walls and a compliant material defining a chamber
120, and each of the flexible walls has one or more active
materials (not shown). Supports between the pleumo-jets 112.sub.a,
112.sub.b, and 112.sub.c are necessary to provide sufficient room
to accommodate the active materials on one or both flexible walls
of each pleumo-jet.
[0024] Each pleumo-jet 112.sub.a, 112.sub.b, and 112.sub.c may
include a single orifice 122 extending from the chambers 120
through the compliant material. The pleumo-jet system 111 may be
arranged such that each of the single orifices 122 of each
pleumo-jet 112.sub.a, 112.sub.b, and 112.sub.c is positioned in the
same direction (FIG. 4). Alternatively, each of the single orifices
122 may be positioned to direct ambient air in a different
direction than the other single orifices 122 (FIG. 3). For any two
adjacent orifices 122, the separation between the orifices 122 may
be in a range between just above zero degrees (0.degree.) to less
than ninety degrees (90.degree.). In one embodiment, adjacent
orifices 122 may be separated by a range of about 5.degree. to
about 45.degree..
[0025] The pleumo-jets 112.sub.a, 112.sub.b, and 112.sub.c are
surrounded by fins 128, which are supported on the base 129. The
fins 128 assist in increasing the surface area for heat transfer
for cooling the electronic components 32.sub.a-d. As with the
previously described pleumo-jet 12, the pleumo-jets 112.sub.a,
112.sub.b, and 112.sub.c utilize active material, for example a
piezoelectric material (not shown), to form streams of ambient air.
Briefly, electrical current from electrical circuitry (shown in
FIG. 8) is received by the active material, and transformed into
mechanical energy. The electrical current can take the form of a
sine wave, a square wave, a triangular wave, or any other suitable
wave form. The voltage level for the electrical current may be
between 1 and 150 volts but is not so limited. The frequency of the
current may be between 2 and 300 hertz for embodiments requiring
reduced noise, and between 300 hertz and 15 kilohertz for
embodiments that do not require reduced noise levels.
[0026] The active material creates stress on the flexible walls,
causing them to flex inwardly, resulting in a chamber volume change
and an influx of ambient air into the chambers 120, and then
outwardly, thereby ejecting the ambient air from the chambers 120
via the orifices 122.
[0027] Another alternative embodiment of a pleumo-jet system is
illustrated in FIG. 5. Specifically, a pleumo-jet system 211 is
illustrated as including a base 229 supporting a pleumo-jet 212.
The pleumo-jet 212 has a plurality of orifices 222, each extending
outwardly in different radial directions. An active material 224 is
shown on a surface of a flexible wall of the pleumo-jet 212. For
any two adjacent orifices 222, the separation between the orifices
222 may be in a range between just above 0.degree. to less than
90.degree.. In one embodiment, adjacent orifices 222 may be
separated by a range of about 5.degree. to about 45.degree..
[0028] FIGS. 6 and 7 illustrate a pleumo-jet 312. The pleumo-jet
312 includes a first flexible wall or structure 314, a second
flexible wall or structure 316, and a compliant material 318
positioned between the flexible walls 314, 316. The walls 314 and
316 are rectangular in shape and, together with the compliant
material 318, form a chamber (not shown). Orifices 322 extend out
through the compliant material 318 from the chamber to the ambient
environment. An active material 324 is positioned on the wall 314,
and optionally an active material 326 may be positioned on the wall
316. The active material can be activated with an electric current
provided by electrical circuitry (not shown) to create stress on
the wall(s) 314 (and 316) to allow for the ingestion of ambient air
into the chamber and the expulsion of the ambient air from the
chamber to the ambient, heated environment.
[0029] FIGS. 8 and 9 illustrate another embodiment of a thermal
management system. A thermal management system 410 is illustrated
as including a piezoelectric fan apparatus 412 in working
relationship with a PCA 30 containing electronic components to be
cooled 32.sub.a-d. The piezo fan apparatus 412 includes one free
end and one end fixed to a support member 420. The piezo fan
apparatus includes a substrate 414 and an active material 416. The
active material 416 may utilize, for example, a piezoceramic
material.
[0030] An electrical circuit 418 is connected to the piezo fan
apparatus 412. Running an electrical current through the piezo fan
apparatus 412 sends an electrical charge through the active
material 416. The active material 416 transforms the electrical
energy into mechanical energy by creating a stress on the substrate
414, causing it to rotate about the fixed end. This creates a
current of ambient air to travel in a direction C (FIG. 8) or in a
direction D (FIG. 9), depending upon the positioning of the piezo
fan apparatus 412 relative to the electronic components to be
cooled 32.sub.a-d.
[0031] Next, and with specific reference to FIG. 10, will be
discussed a process for forming a pleumo-jet in accordance with an
embodiment of the invention. At Step 500, a pair of flexible
structures is provided. The flexible structures may be metallic or
they may be non-metallic, such as plastic or polymer composite
material. Examples of the flexible structures include flexible
walls 14, 16 (FIGS. 1, 2) and flexible walls 314, 316 (FIGS. 6, 7).
One or both of the flexible structures require an active material
that is excitable by an electrical stimulus to be affixed thereon.
Suitable examples of active material include material 24, 26 (FIGS.
1, 2) and material 324, 326 (FIGS. 6, 7).
[0032] At Step 505, a compliant material is attached between the
flexible structures. The compliant material may be compliant
material 18 (FIGS. 1, 2) or compliant material 318 (FIGS. 6, 7).
The compliant material is to be provided in such a form as to
define a chamber between the flexible structures. One process for
providing the compliant material is to dispense the compliant
material in a liquid or semi-liquid form onto one of the flexible
structures, placing the other conductive structure on the compliant
material, and allowing the compliant material to dry. A liquid
silicone-based material may be suitable for such a process. Another
process for providing the compliant material is to cut the
compliant material from a pre-made sheet of compliant material, and
bonding the pre-made sheet of cut compliant material to the
flexible structures. A pre-made silicone-based sheet of material
may be suitable for this process.
[0033] At Step 510, electrical contacts are provided to the
flexible structures. Electrical circuitry will be attached to the
electrical contacts.
[0034] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
* * * * *