Thermoacoustic refrigerator

Claim 2

A thermoacoustic device comprising: a housing; a transducer, said transducer disposed within said housing; a first heat exchanger, said first heat exchanger disposed within said housing; a second heat exchanger, said second heat exchanger disposed within said housing; and a thermal stack comprising a single piece of porous material, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger and such that thermal stack directly adjoins said second heat exchanger such that a gas may be dispersed throughout said housing and throughout said pore space of said thermal stack such that, upon the activation of said transducer, an oscillating wave form is produced within said gas so as to compress and decompress said gas and form a temperature gradient within said thermal stack.

Claim 3

The thermoacoustic device of claim 1 wherein said thermal stack comprises a porous carbon material.

Claim 4

The thermoacoustic device of claim 1 wherein said thermal stack comprises reticulated vitreous carbon.

Claim 5

The thermoacoustic device of claim 1 wherein said thermal stack has a shape and where said shape is formed by machining a piece of reticulated vitreous carbon.

Claim 6

The thermoacoustic device of claim 1 wherein said thermal stack has a shape and wherein said shape is cylindrical.

Claim 7

The thermoacoustic device of claim 1 wherein said thermal stack has an outer surface which has a shape and wherein said outer surface shape is the shape of a venturi tube.

Claim 8

The thermoacoustic device of claim 1 wherein said thermal stack has a shape and wherein said shape is u-shaped.

Claim 9

The thermoacoustic device of claim 1 wherein said thermal stack has a shape and said shape has two ends and a central region and wherein said diameter varies along the length of said thermal stack such that each of said ends has a diameter and such that said central region has a diameter and wherein said diameter of said central region is less than said diameter of each of said ends.

Claim 10

The thermoacoustic device of claim 1 wherein said first heat exchanger comprises a piece of thermally conductive open cell foam material.

Claim 11

The thermoacoustic device of claim 1 wherein said thermal stack has a shape and wherein said shape has two ends and a central region and wherein said diameter varies along the length of said thermal stack such that each of said ends has a diameter and such that said central region has a diameter and wherein said diameter of said central region is greater than said diameter of each of said ends.

Claim 12

The thermoacoustic device of claim 1 wherein said thermal stack has a shape and wherein said shape is hexagonal.

Claim 13

The thermoacoustic device of claim 1 wherein said thermal stack has a shape and wherein said shape is octagonal.

Claim 14

The thermoacoustic device as recited in claim 1 wherein said thermal stack comprises a piece of reticulated vitreous carbon material and wherein said thermal stack is formed by cutting a piece of reticulated vitreous carbon material.

Claim 15

The thermoacoustic device as recited in claim 1 wherein said thermal stack comprises a piece of reticulated vitreous carbon material and wherein said thermal stack is formed by machining a piece of reticulated vitreous carbon material.

Claim 16

A semiconductor package including a thermoacoustic cooling device comprising: a housing; a transducer, said transducer disposed within said housing; a first heat exchanger, said first heat exchanger disposed within said housing; a semiconductor device, said semiconductor device disposed within said housing and connected to said first heat exchanger; a second heat exchanger, said second heat exchanger disposed within said housing; and a thermal stack comprising a piece of porous material, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger and such that thermal stack directly adjoins said second heat exchanger such that a gas may be dispersed throughout said housing and throughout said pore space of said thermal stack such that, upon the activation of said transducer and said semiconductor device, an oscillating wave form may be produced within said gas so as to compress and decompress said gas so as to form a temperature gradient within said thermal stack, and such that said semiconductor device generates heat, and such that said heat of said semiconductor device is transferred through said gas to said second heat exchanger.

Claim 17

A semiconductor package including a thermoacoustic cooling device comprising: a housing; a transducer, said transducer disposed within said housing; a first heat exchanger, said first heat exchanger disposed within said housing; a semiconductor device, said semiconductor device disposed within said housing and connected to said first heat exchanger; a second heat exchanger, said second heat exchanger disposed within said housing; and a thermal stack comprising a piece of porous material, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger and such that thermal stack directly adjoins said second heat exchanger such that a gas may be dispersed throughout said housing and throughout said pore space of said thermal stack such that, upon the activation of said transducer and said semiconductor device, an oscillating wave form may be produced within said gas so as to compress and decompress said gas so as to form a temperature gradient within said thermal stack, and such that said semiconductor device generates heat, and such that said heat of said semiconductor device is transferred through said gas to said second heat exchanger.

Claim 18

The semiconductor package of claim 15 wherein said first heat exchanger comprises a thermally conductive open cell foam material.

Claim 19

The semiconductor package of claim 15 wherein said thermal stack comprises reticulated vitreous carbon.

Claim 20

A micro-thermoacoustic device comprising: a housing; a transducer, said transducer disposed within said housing; a first heat exchanger, said first heat exchanger disposed within said housing; a second heat exchanger, said second heat exchanger disposed within said housing; and a thermal stack comprising a single piece of porous material, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger and such that thermal stack directly adjoins said second heat exchanger such that a gas may be dispersed throughout said housing and throughout said pore space of said thermal stack such that, upon the activation of said transducer, an oscillating wave form is produced within said gas so as to compress and decompress said gas so as to form a temperature gradient within said thermal stack.

Claim 21

A micro-thermoacoustic device comprising: a housing; a transducer, said transducer disposed within said housing; a first heat exchanger, said first heat exchanger disposed within said housing; a second heat exchanger, said second heat exchanger disposed within said housing; and a thermal stack comprising a single piece of porous material, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger and such that thermal stack directly adjoins said second heat exchanger such that a gas may be dispersed throughout said housing and throughout said pore space of said thermal stack such that, upon the activation of said transducer, an oscillating wave form is produced within said gas so as to compress and decompress said gas so as to form a temperature gradient within said thermal stack.

Claim 22

The micro-thermoacoustic device as recited in claim 18 wherein said transducer has a frequency and wherein said frequency is greater than one kilohertz.

Claim 23

The micro-thermoacoustic device as recited in claim 18 wherein said single piece of porous material comprises reticulated vitreous carbon.

Claim 24

The micro-thermoacoustic device as recited in claim 18 wherein said single piece of porous material comprises a piece of porous carbon material and wherein said single piece of material is formed by cutting a piece of reticulated vitreous carbon material.

Claim 25

The micro-thermoacoustic device as recited in claim 18 wherein said single piece of material comprises a piece of porous carbon material and wherein said single piece of material is formed by machining a piece of reticulated vitreous carbon material.

Claim 26

The micro-thermoacoustic device as recited in claim 18 wherein said single piece of material has a shape and wherein said shape is cylindrical.

Claim 27

The micro-thermoacoustic device as recited in claim 18 wherein said first heat exchanger comprises diamond.

Claim 28

The micro-thermoacoustic device as recited in claim 18 wherein said housing has a length and a diameter and wherein said diameter is less than one centimeter and wherein said length is less than fifteen centimeters.

Claim 29

The micro-thermoacoustic device as recited in claim 18 wherein said housing has a diameter and wherein said housing has a length and wherein said length is approximately twelve centimeters and wherein said diameter is approximately one centimeter.

Claim 30

The micro-thermoacoustic device as recited in claim 18 wherein said single piece of material has an internal structure which includes pin shaped elements and wherein said pin shaped elements have surfaces, said surfaces of said pin shaped elements being rounded.

Claim 31

The micro-thermoacoustic device as recited in claim 27 wherein said surfaces of said pin shaped elements define a surface area and wherein said surface area is easily altered by forming said single piece of material from a piece of material having the required surface area.

Claim 32

The micro-thermoacoustic device as recited in claim 27 wherein said pin shaped elements of said single piece of material defines a plurality of circular structures, and wherein said number of circular structures is easily altered by forming said single piece of material from a piece of material having the required number of circular structures per linear inch.

Claim 33

The thermal stack for a micro-thermoacoustic device of claim 29 wherein said transducer operates at a frequency of approximately two kilohertz.

Claim 34

A thermoacoustic device comprising: a housing; a transducer, said transducer disposed within said housing; a heat exchanger comprising a piece of thermally conductive open cell foam, said piece of thermally conductive open cell foam having pore space, said heat exchanger disposed within said housing; and a thermal stack, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger such that a gas may be dispersed throughout said housing and throughout said pore space of said thermal stack and throughout said pore space of said heat exchanger such that, upon the activation of said transducer, a temperature gradient is formed within said thermal stack such that heat may be transferred to said thermal stack by said heat exchanger.

Claim 35

A thermoacoustic device comprising: a housing; a transducer, said transducer disposed within said housing; a heat exchanger comprising a piece of thermally conductive open cell foam, said piece of thermally conductive open cell foam having pore space, said heat exchanger disposed within said housing; and a thermal stack, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger such that a gas may be dispersed throughout said housing and throughout said pore space of said thermal stack and throughout said pore space of said heat exchanger such that, upon the activation of said transducer, a temperature gradient is formed within said thermal stack such that heat may be transferred to said thermal stack by said heat exchanger.

Claim 36

The thermoacoustic device of claim 31 further comprising a heat exchanger for heat removal, said heat exchanger for heat removal including open cell foam material, said heat exchanger for heat removal disposed within said housing such that heat may be moved out of said device through said heat exchanger for heat removal.

Claim 37

The thermoacoustic device of claim 31 wherein said piece of thermally conductive open cell foam comprises a metal foam.

Claim 38

The thermoacoustic device of claim 32 wherein said heat exchanger includes a first retainer ring and a first heat conducting element and wherein heat is moved into said thermoacoustic device through said first heat conducting element and wherein said heat exchanger for heat removal includes a second retainer ring and a second heat conducting element, and wherein heat is moved out of said thermoacoustic device through said second heat conducting element.

Claim 39

The thermoacoustic device of claim 31 wherein said piece of thermally conductive open cell foam comprises a aluminum foam.

Claim 40

The thermoacoustic device of claim 31 wherein said piece of thermally conductive open cell foam comprises a copper foam.

Claim 41

The thermoacoustic device of claim 31 wherein said piece of thermally conductive open cell foam comprises a silver foam.

Claim 42

The thermal stack for a micro-thermoacoustic device of claim 31 wherein said solid piece of porous material has a shape and wherein said shape has two ends, a length and a central region and wherein said diameter varies along the length of said piece of material such that each of said ends has a diameter and such that said central region has a diameter and wherein said central region has a diameter greater than said diameter of each of said ends.

Claim 43

A micro-thermoacoustic cooling device comprising: a cylindrical housing having an enclosed end and an open end; a micro-transducer, said micro-transducer disposed within said housing such that said micro-transducer lies within said open end of said housing so as to enclose said open end of said housing; a first heat exchanger comprising a piece of porous material, said first heat exchanger disposed within said housing, said first heat exchanger including a region containing openings such that said gas may pass through said region of said first heat exchanger containing said openings; a second heat exchanger comprising a piece of porous material, said second heat exchanger disposed within said housing, said second heat exchanger including a region containing openings such that said gas may pass through said region of said second heat exchanger containing said openings; and a thermal stack comprising a single piece of reticulated vitreous carbon, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger and such that thermal stack directly adjoins said second heat exchanger, such that a gas may be disposed within said pore space of said thermal stack such that, upon the activation of said micro-transducer, a wave form is produced so as to form a temperature gradient within said thermal stack such that, upon the transfer of heat to said first heat exchanger, said heat transferred to said first heat exchanger is transferred through said gas disposed within said pore space of said thermal stack to said second heat exchanger.

Claim 44

A micro-thermoacoustic cooling device comprising: a cylindrical housing having an enclosed end and an open end; a micro-transducer, said micro-transducer disposed within said housing such that said micro-transducer lies within said open end of said housing so as to enclose said open end of said housing; a first heat exchanger comprising a piece of porous material, said first heat exchanger disposed within said housing, said first heat exchanger including a region containing openings such that said gas may pass through said region of said first heat exchanger containing said openings; a second heat exchanger comprising a piece of porous material, said second heat exchanger disposed within said housing, said second heat exchanger including a region containing openings such that said gas may pass through said region of said second heat exchanger containing said openings; and a thermal stack comprising a single piece of reticulated vitreous carbon, said thermal stack having pore space, said thermal stack disposed within said housing such that said thermal stack directly adjoins said first heat exchanger and such that thermal stack directly adjoins said second heat exchanger, such that a gas may be disposed within said pore space of said thermal stack such that, upon the activation of said micro-transducer, a wave form is produced so as to form a temperature gradient within said thermal stack such that, upon the transfer of heat to said first heat exchanger, said heat transferred to said first heat exchanger is transferred through said gas disposed within said pore space of said thermal stack to said second heat exchanger.

Claim 45

The micro-thermoacoustic device of claim 39 wherein said thermal stack is formed by machining a single piece of reticulated vitreous carbon material.

Claim 46

The micro-thermoacoustic device of claim 40 wherein said first heat exchanger comprises a thermally conductive open cell foam material.

Claim 47

The micro-thermoacoustic device of claim 40 wherein said second heat exchanger comprises a thermally conductive open cell foam material.