Detailed Action
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Interpretation
Claim 1 is a product claim and recites “a heat exchanger material for use in heat exchangers of cryogenic cooling systems” and “solid material rendered into a final form by an additive manufacturing process”. Neither of these limitations provide a structure to the product and thus the prior art will be interpreted based its suitability for use in the claimed system and suitability for being formed using additive manufacturing. Examiner notes that an extremely broad range of shapes/sizes and materials can be used in additive manufacturing.
Claim 5 recites “mesh-formed” and “matrix-formed”. These terms are interpreted as require a mesh or matrix structure, instead of the formation technique being a mesh or matrix.
The claims recite a plurality of intended use limitations for the product claims such as “a “a liquid cryogen space” (Claim 14); liquid cryogen vessel” (Claim 15); “for a liquid cryogen” (Claim 16). The claims do not specify the structure required to qualify something as a space for liquid cryogen. The prior art will be applied based on whether it meets the structural requirements of the product claim.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-2, 4-6, and 14-23 are rejected under 35 U.S.C. 103 as being unpatentable over Schmidt (US20060245987A1) in view of Chauhan (US20160146556A1), further in view of Poltorak (US20200149832A1).
Claim 1
Schmidt teaches a heat exchanger material (Figure 7 teaches a heat exchanger (10f) for use with two fluid flows (12f and 14f) passing through heat exchange material (16f).) for use in heat exchangers of cryogenic cooling systems (Claim 1 is a product claim, and thus the intended use of “for use in heat exchangers of cryogenic cooling systems” is the intended use of the material. The heat exchanger of Schmidt has the claimed structural limitations and thus is capable of performing the claimed intended use.), the heat exchanger material comprising solid material rendered into a final form by an additive manufacturing process (¶0035 discusses the manufacturing methods of the porous network can be additive microfabrication techniques.), the heat exchanger material having a surface-to-volume ratio of at least 10^5 1/m (¶0023 teaches the surface area density ratio can be 5,000 1/m or greater, thus the range presented by Schmidt is ratio >/= 5000 1/m. This is an overlapping range.), and the heat exchanger material comprising a plurality of extended thermal conduction paths in a form of regularly shaped portions of said solid material that extend through a majority of a thickness of the heat exchanger material (Figure 7 shows the flow paths (12f 14f) pass through the material (16f). Figure 9 shows an example of the material where the material is made up of a plurality of “regularly shaped portions”. The function of the heat exchanger in Figure 7 is such that the fluid flows through the entire length/width of the material.); wherein the heat exchanger material comprises a recursively repeating surface structure exhibiting a fractal pattern (Figure 9 and ¶0035 show the use of a fractal pattern for the heat exchanger material.), in which surface features of a first characteristic dimension comprise the surface features of a second characteristic dimension smaller than said first characteristic dimension. (Figure 9 and ¶0035 show the use of a fractal pattern for the heat exchanger material. A fractal pattern has the claimed dimensions.)
Schmidt does not explicitly disclose the claimed range for the surface area to volume ratio of 10^5 1/m to infinity. Schmidt does disclose the use of a fractal design and that is formed by additive manufacturing, a technique which can generate virtually any desired shape/size for the material.
However, Chauhan teaches the formation of a heat exchanger material that has a surface area to volume ratio of greater than 10^5 1/m. (¶0032 and ¶0036 teach first and second surface area to volume ratios for the material that are above 10^5 1/m. ¶0028 teaches this material can be used for heat transfer (thermal interface/heat spreader).)
One of ordinary skill would have been motivated to apply the known technique of using a high surface to volume ratio (10^5 1/m and above) of Chauhan to the heat exchanger design and formation method of Schmidt in order to provide a higher heat transfer property to the device of Schmidt. (See ¶0032 of Chauhan)
This is further motivated and evidenced by Poltorak. Poltorak discloses a fractal heat exchanger material (¶0069) made from additive manufacturing (¶0083 “modern three dimensional laser…printers”) that exhibits a theoretical infinite surface area (¶0068 “three dimensional fractals…are characterized by infinite surface area”). Poltorak further teaches that this large surface area causes increased heat transfer (¶0069) and fractals allow for the obtaining of this feature (¶0070).
Therefore, it would have been obvious to one of ordinary skill in the art, at the time the invention was effectively filed, to apply the known apply the known technique of using a high surface to volume ratio (10^5 1/m and above) of Chauhan to the heat exchanger design and formation method of Schmidt because it has been held to be prima facie obvious to apply a known technique to a known method/apparatus to yield predictable results. See MPEP 2143(I)(D).
The predictable result is that Schmidt’s fractal build dimensions will be chosen to create a heat exchanger with a high (above 10^5 1/m) surface area to volume ratio. Chauhan teaches this ratio is advantageous and Poltorak teaches this is possible using an additively manufactured fractal design.
Claim 2
Schmidt in view of Chauhan and Poltorak teaches the heat exchanger material according to claim 1, wherein the plurality of extended thermal conduction paths in the form of regularly shaped portions of said solid material occur in a repetitive pattern throughout a layer of said heat exchanger material. (Schmidt, Figures 7-9 teach various view of heat exchanger material where portions of the solid material are repeated throughout the layers of material.)
Claim 4
Schmidt in view of Chauhan and Poltorak teaches the heat exchanger material according to claim 1, said heat exchanger material defining a recursive spatial form (Schmidt, Figure 9 teaches the fractal-like design has a recursive form in that it features repeating smaller forms of “surface features” extending from one another.) in which first spatial features of a piece of said heat exchanger material have a first characteristic dimension and consist of second, similar spatial features of a second characteristic dimension smaller than said first characteristic dimension. (Schmidt, Figure 9 teaches the fractal-like design has a recursive form in that it features repeating smaller forms of “surface features” extending from one another. ¶0035 teaches the use of a fractal design. A fractal has the claimed dimensional relationship between pieces of the heat exchanger material.)
Claim 5
Schmidt in view of Chauhan and Poltorak teaches the heat exchanger material according to claim 1, wherein at least one surface of the heat exchanger material comprises a maze defined by a plurality of mesh-formed or matrix-formed layers stacked on top of a solid surface of said heat exchanger material, at least some of said mesh-formed or matrix-formed layers having solid stretches that bridge openings in a respective adjacent mesh-formed or matrix-formed layer. (Schmidt teaches the heat exchanger (10f) has flow paths (12f, 14f), meaning that there is openings within the mesh material (16f) forming the “heat exchanger material”. Figures 7 or 9 show an example of the material (16f) as a mesh or matrix form having solid stretches. ¶0035 teaches the material is formed using freeform fabrication, meaning that it is formed of layers stacked atop one another as claimed.)
Claim 6
Schmidt in view of Chauhan and Poltorak teaches the heat exchanger material according to claim 1, wherein said solid material comprises at least one of the following: copper, silver, and plastic. (Schmidt ¶0036 teaches the material can be a polymer or metal.)
Claim 14
Schmidt in view of Chauhan and Poltorak teaches a heat exchanger for transferring thermal energy to or from a liquid cryogen (Schmidt, Figure 7 teaches a heat exchanger (10f) for exchanging heat between two fluid flows (¶0006). There is no specific structure in the product claim that indicates what is special about a heat exchanger for liquid cryogen. Therefore, Schmidt’s heat exchanger teaches the claimed structure and the intended use of Claim 14.), the heat exchanger comprising a surface of a liquid cryogen space (As noted above, the “of a liquid cryogen” is the intended use of the space. Schmidt, Figure 7 shows a flow path (12f, 14f) that is a space for fluid to flow through the exchanger. There is solid material (the portions of the heat exchanger that are not illustrated as a mesh) that is the claimed surface.) and, as a part of said surface, the heat exchanger material according to claim 1. (Figure 7 shows the material (16f) extends from the surface of the heat exchanger in the flow path(s) (12f, 14f). See the rejection of Claim 1 above.)
Claim 15
Schmidt in view of Chauhan and Poltorak teaches the heat exchanger according to claim 14, further comprising a liquid cryogen vessel divided into at least two separate liquid cryogen spaces by a partition wall, so that said surface of said liquid cryogen space comprises at least one surface of said partition wall. (Schmidt, Figure 7 shows the heat exchanger (10f) has a partition wall in between each of the flow paths (12f, 14f). The flow paths are the claimed “liquid cryogen spaces” since that is where the fluid flows during operation of the heat exchanger.)
Claim 16
Schmidt in view of Chauhan and Poltorak teaches a cryogenic cooling system (This is the intended use of the system. Schmidt’s heat exchanger (Figure 7) meets the structural requirements of the product claim and is capable of performing the intended use.) comprising: a flow path for a liquid cryogen (Schmidt, Figure 7 shows two flow paths (12f, 14f) that extend from outside the heat exchanger (10f), then through the specific flow areas within the heat exchanger.), and along said flow path, at least one heat exchanger (Schmidt, Item 10f) for transferring thermal energy to or from the liquid cryogen flowing through said flow path (Schmidt, ¶0006 teaches the heat exchanger is used for transferring heat between two fluids. Thus, Schmidt teaches a heat exchanger capable of performing the claimed intended use.); wherein said at least one heat exchanger comprises the heat exchanger material according to claim 1 (See the rejection of Claim 1 above.), and wherein said solid material is exposed to liquid cryogen on said flow path. (Schmidt, Figure 7 shows the flow path (12f, 14f) passes through the material (16f). Therefore, the fluid flowing along the flow paths contacts the solid material.)
Claim 17
Schmidt teaches a heat exchanger material (Figure 7 teaches a heat exchanger (10f) for use with two fluid flows (12f and 14f) passing through heat exchange material (16f).) for use in heat exchangers of cryogenic cooling systems (Claim 1 is a product claim, and thus the intended use of “for use in heat exchangers of cryogenic cooling systems” is the intended use of the material. The heat exchanger of Schmidt has the claimed structural limitations and thus is capable of performing the claimed intended use.), the heat exchanger material comprising solid material rendered into a final form by an additive manufacturing process (¶0035 discusses the manufacturing methods of the porous network can be additive microfabrication techniques.), the heat exchanger material having a surface-to-volume ratio of at least 10^5 1/m (¶0023 teaches the surface area density ratio can be 5,000 1/m or greater, thus the range presented by Schmidt is ratio >/= 5000 1/m. This is an overlapping range.), and the heat exchanger material comprising a plurality of extended thermal conduction paths in a form of regularly shaped portions of said solid material that extend through a majority of a thickness of the heat exchanger material (Figure 7 shows the flow paths (12f 14f) pass through the material (16f). Figure 9 shows an example of the material where the material is made up of a plurality of “regularly shaped portions”. The function of the heat exchanger in Figure 7 is such that the fluid flows through the entire length/width of the material.); wherein the heat exchanger material comprises a recursively repeating surface structure (Figure 9 and ¶0035 show the use of a fractal pattern for the heat exchanger material. This is a recursively repeating structure.), in which three-dimensional elements of a first characteristic dimension comprise the three-dimensional elements of a second characteristic dimension smaller than said first characteristic dimension. (Figure 9 and ¶0035 show the use of a fractal pattern for the heat exchanger material. A fractal pattern has the claimed three dimensional elements connected to smaller three dimensional elements.)
Schmidt does not explicitly disclose the claimed range for the surface area to volume ratio of 10^5 1/m to infinity. Schmidt does disclose the use of a fractal design and that is formed by additive manufacturing, a technique which can generate virtually any desired shape/size for the material.
However, Chauhan teaches the formation of a heat exchanger material that has a surface area to volume ratio of greater than 10^5 1/m. (¶0032 and ¶0036 teach first and second surface area to volume ratios for the material that are above 10^5 1/m. ¶0028 teaches this material can be used for heat transfer (thermal interface/heat spreader).)
One of ordinary skill would have been motivated to apply the known technique of using a high surface to volume ratio (10^5 1/m and above) of Chauhan to the heat exchanger design and formation method of Schmidt in order to provide a higher heat transfer property to the device of Schmidt. (See ¶0032 of Chauhan)
This is further motivated and evidenced by Poltorak. Poltorak discloses a fractal heat exchanger material (¶0069) made from additive manufacturing (¶0083 “modern three dimensional laser…printers”) that exhibits a theoretical infinite surface area (¶0068 “three dimensional fractals…are characterized by infinite surface area”). Poltorak further teaches that this large surface area causes increased heat transfer (¶0069) and fractals allow for the obtaining of this feature (¶0070).
Therefore, it would have been obvious to one of ordinary skill in the art, at the time the invention was effectively filed, to apply the known apply the known technique of using a high surface to volume ratio (10^5 1/m and above) of Chauhan to the heat exchanger design and formation method of Schmidt because it has been held to be prima facie obvious to apply a known technique to a known method/apparatus to yield predictable results. See MPEP 2143(I)(D).
The predictable result is that Schmidt’s fractal build dimensions will be chosen to create a heat exchanger with a high (above 10^5 1/m) surface area to volume ratio. Chauhan teaches this ratio is advantageous and Poltorak teaches this is possible using an additively manufactured fractal design.
Claim 18
Schmidt in view of Chauhan and Poltorak teaches the heat exchanger material of claim 17, wherein the three-dimensional elements of the first characteristic dimension comprising the three-dimensional elements of the second characteristic dimension increases said surface-to-volume ratio by increasing a degree of recursion of said recursively repeating surface structure. (Schmidt, Figure 9 shows that the fractal structure consists of three-dimensional elements layered on one another in a smaller and smaller size, which is an increase of recursion of the structure. This is also the definition of a fractal structure. Poltorak, ¶0068 teaches that a fractal is formed of shapes connected to reduces sized copies (increased recursion) and that three dimensional fractals allow for infinite surface area.)
Claim 19
Schmidt teaches a heat exchanger material (Figure 7 teaches a heat exchanger (10f) for use with two fluid flows (12f and 14f) passing through heat exchange material (16f).) for use in heat exchangers of cryogenic cooling systems (Claim 1 is a product claim, and thus the intended use of “for use in heat exchangers of cryogenic cooling systems” is the intended use of the material. The heat exchanger of Schmidt has the claimed structural limitations and thus is capable of performing the claimed intended use.), the heat exchanger material comprising solid material rendered into a final form by an additive manufacturing process (¶0035 discusses the manufacturing methods of the porous network can be additive microfabrication techniques.), the heat exchanger material having a surface-to-volume ratio of at least 10^5 1/m (¶0023 teaches the surface area density ratio can be 5,000 1/m or greater, thus the range presented by Schmidt is ratio >/= 5000 1/m. This is an overlapping range.), and the heat exchanger material comprising a plurality of extended thermal conduction paths in a form of regularly shaped portions of said solid material that extend through a majority of a thickness of the heat exchanger material (Figure 7 shows the flow paths (12f 14f) pass through the material (16f). Figure 9 shows an example of the material where the material is made up of a plurality of “regularly shaped portions”. The function of the heat exchanger in Figure 7 is such that the fluid flows through the entire length/width of the material.); wherein the heat exchanger material comprises a recursively repeating surface structure (Figure 9 and ¶0035 show the use of a fractal pattern for the heat exchanger material. This is a recursively repeating structure.), in which a first spatial surface feature of a first degree of recursion of said material has a first characteristic size and comprised in said first surface feature are a plurality of second, similar spatial surface features of a second characteristic dimension smaller than said first characteristic dimension, said second spatial surface features thus forming a second degree of recursion of said material. (Figure 9 and ¶0035 show the use of a fractal pattern for the heat exchanger material. A fractal pattern has the claimed first spatial surface features connected to similar, smaller spatial surface features.)
Schmidt does not explicitly disclose the claimed range for the surface area to volume ratio of 10^5 1/m to infinity. Schmidt does disclose the use of a fractal design and that is formed by additive manufacturing, a technique which can generate virtually any desired shape/size for the material.
However, Chauhan teaches the formation of a heat exchanger material that has a surface area to volume ratio of greater than 10^5 1/m. (¶0032 and ¶0036 teach first and second surface area to volume ratios for the material that are above 10^5 1/m. ¶0028 teaches this material can be used for heat transfer (thermal interface/heat spreader).)
One of ordinary skill would have been motivated to apply the known technique of using a high surface to volume ratio (10^5 1/m and above) of Chauhan to the heat exchanger design and formation method of Schmidt in order to provide a higher heat transfer property to the device of Schmidt. (See ¶0032 of Chauhan)
This is further motivated and evidenced by Poltorak. Poltorak discloses a fractal heat exchanger material (¶0069) made from additive manufacturing (¶0083 “modern three dimensional laser…printers”) that exhibits a theoretical infinite surface area (¶0068 “three dimensional fractals…are characterized by infinite surface area”). Poltorak further teaches that this large surface area causes increased heat transfer (¶0069) and fractals allow for the obtaining of this feature (¶0070).
Therefore, it would have been obvious to one of ordinary skill in the art, at the time the invention was effectively filed, to apply the known apply the known technique of using a high surface to volume ratio (10^5 1/m and above) of Chauhan to the heat exchanger design and formation method of Schmidt because it has been held to be prima facie obvious to apply a known technique to a known method/apparatus to yield predictable results. See MPEP 2143(I)(D).
The predictable result is that Schmidt’s fractal build dimensions will be chosen to create a heat exchanger with a high (above 10^5 1/m) surface area to volume ratio. Chauhan teaches this ratio is advantageous and Poltorak teaches this is possible using an additively manufactured fractal design.
Claim 20
Schmidt in view of Chauhan and Poltorak teaches a heat exchanger for transferring thermal energy to or from a liquid cryogen (Schmidt, Figure 7 teaches a heat exchanger (10f) for exchanging heat between two fluid flows (¶0006). There is no specific structure in the product claim that indicates what is special about a heat exchanger for liquid cryogen. Therefore, Schmidt’s heat exchanger teaches the claimed structure and the intended use of Claim 14.), the heat exchanger comprising a surface of a liquid cryogen space (As noted above, the “of a liquid cryogen” is the intended use of the space. Schmidt, Figure 7 shows a flow path (12f, 14f) that is a space for fluid to flow through the exchanger. There is solid material (the portions of the heat exchanger that are not illustrated as a mesh) that is the claimed surface.) and, as a part of said surface, the heat exchanger material according to claim 17. (Schmidt, Figure 7 shows the material (16f) extends from the surface of the heat exchanger in the flow path(s) (12f, 14f). See the rejection of Claim 17 above.)
Claim 21
Schmidt in view of Chauhan and Poltorak teaches a heat exchanger for transferring thermal energy to or from a liquid cryogen (Schmidt, Figure 7 teaches a heat exchanger (10f) for exchanging heat between two fluid flows (¶0006). There is no specific structure in the product claim that indicates what is special about a heat exchanger for liquid cryogen. Therefore, Schmidt’s heat exchanger teaches the claimed structure and the intended use of Claim 14.), the heat exchanger comprising a surface of a liquid cryogen space (As noted above, the “of a liquid cryogen” is the intended use of the space. Schmidt, Figure 7 shows a flow path (12f, 14f) that is a space for fluid to flow through the exchanger. There is solid material (the portions of the heat exchanger that are not illustrated as a mesh) that is the claimed surface.) and, as a part of said surface, the heat exchanger material according to claim 19. (Schmidt, Figure 7 shows the material (16f) extends from the surface of the heat exchanger in the flow path(s) (12f, 14f). See the rejection of Claim 19 above.)
Claim 22
Schmidt in view of Chauhan and Poltorak teaches a cryogenic cooling system (This is the intended use of the system. Schmidt’s heat exchanger (Figure 7) meets the structural requirements of the product claim and is capable of performing the intended use.) comprising: a flow path for a liquid cryogen (Schmidt, Figure 7 shows two flow paths (12f, 14f) that extend from outside the heat exchanger (10f), then through the specific flow areas within the heat exchanger.), and along said flow path, at least one heat exchanger (Schmidt, Item 10f) for transferring thermal energy to or from the liquid cryogen flowing through said flow path (Schmidt, ¶0006 teaches the heat exchanger is used for transferring heat between two fluids. Thus, Schmidt teaches a heat exchanger capable of performing the claimed intended use.); wherein said at least one heat exchanger comprises the heat exchanger material according to claim 17 (See the rejection of Claim 17 above.), and wherein said solid material is exposed to liquid cryogen on said flow path. (Schmidt, Figure 7 shows the flow path (12f, 14f) passes through the material (16f). Therefore, the fluid flowing along the flow paths contacts the solid material.)
Claim 23
Schmidt in view of Chauhan and Poltorak teaches a cryogenic cooling system (This is the intended use of the system. Schmidt’s heat exchanger (Figure 7) meets the structural requirements of the product claim and is capable of performing the intended use.) comprising: a flow path for a liquid cryogen (Schmidt, Figure 7 shows two flow paths (12f, 14f) that extend from outside the heat exchanger (10f), then through the specific flow areas within the heat exchanger.), and along said flow path, at least one heat exchanger (Schmidt, Item 10f) for transferring thermal energy to or from the liquid cryogen flowing through said flow path (Schmidt, ¶0006 teaches the heat exchanger is used for transferring heat between two fluids. Thus, Schmidt teaches a heat exchanger capable of performing the claimed intended use.); wherein said at least one heat exchanger comprises the heat exchanger material according to claim 19 (See the rejection of Claim 19 above.), and wherein said solid material is exposed to liquid cryogen on said flow path. (Schmidt, Figure 7 shows the flow path (12f, 14f) passes through the material (16f). Therefore, the fluid flowing along the flow paths contacts the solid material.)
Response to Arguments
Applicant's arguments filed 11/07/2025 have been fully considered but they are not persuasive.
Applicant argues that claim limitations “a heat exchanger material for use in heat exchangers of cryogenic cooling systems” and “a liquid cryogen space” invoke specific structures when read by a PHOSITA.
It is respectfully asserted that these limitations are the intended use of the structure(s) required by the claims. Applicant does not specify the structure or specific class of materials required by these intended use limitations in the claims. If there is written description support for these specific materials or structures as asserted, they can be added to the claim to more precisely define the structure of the product and limit the claim as intended by the applicant.
Applicant argues that Schmidt does not teach “the heat exchanger material comprises a plurality of extended thermal conduction paths in a form of regularly shaped portions of said solid material that extend through a majority of a thickness of the heat exchanger material”.
It is respectfully asserted that Schmidt teaches the claim limitation and the rejection is proper. As a preliminary note, the argued limitation contains multiple limitations that allow for a broader interpretation of the claim(s) than may be intended by the applicant. The terms “extended”, “regularly”, “majority of a thickness” all can be interpreted in multiple ways. As to the prior art, a more detailed analysis of the alleged undisclosed limitation is as follows: Schmidt teaches a heat exchanger (Figure 7) that includes a material (the material of the heat exchanger flow paths) that forms “thermal conduction paths” (fluid flows 12f/14f) that are “extended” (applicant does not define the length required for “extended”) in a form of regularly shaped portions (Applicant does not define “regularly”. The solid portions of the flow paths of Schmidt are “regularly shaped” in that they have a pattern.) that extend through a majority (Applicant does not define the extend required for majority. The broadest reasonable interpretation is at least 51%.) of a thickness of the heat exchanger material (Applicant does not define which direction the thickness is being measured. As shown in Figure 7 of Schmidt, the flow paths (12f/14f) contain the “regularly shaped” material along the entire thickness of the heat exchanger in the horizontal direction and the entire thickness of the flow path in the vertical direction.) This does not represent a change in the rejection above or a new rejection. Therefore, Schmidt teaches the claim limitation under the broadest reasonable interpretation of the plurality of ambiguous terms in the claim(s) and the rejection is proper.
Applicant argues that Schmidt does not teach “a heat exchanger material has a surface-to-volume ratio of at least 10^5 1/m”.
It is respectfully asserted that the combination of reference arrives at the claimed open ended dimensional limitation as recited by the applicant. Although applicant argues that Schmidt only teaches a ratio of 5000 1/m, this is not in line the rejection above or the disclosure of the reference. Schmidt explicitly states the range to be open ended (¶0023), such that surface area to volume ratios disclosed by the reference at 5000 1/m or more. This is an open ended range that overlaps with applicant’s claimed range. To teach the specific values claimed by applicant, Chauhan is relied upon as an analogous (in the field of heat exchangers) device that has the claimed ratio (10^5 1/m or greater)( ¶0032). Schmidt teaches additive microfabrication or freeform fabrication techniques (¶0035), which are known to be capable of, and intended to form microscopic shapes/structures. Schmidt also discloses the use fractal designs (¶0035), which is known in the art as being used to create very high surface are to volume ratios for heat exchangers, as explained in the rejection based on the evidence in Poltorak. Therefore, even if the method of manufacture is different in Chauhan, Schmidt teaches an open-ended range that includes the claimed ratio and manufacturing techniques that are configured to create a heat exchanger material that has the claimed ratio.
Applicant argues against the disclosure of Poltorak, specifically that ¶0068 does not teach infinite surface area.
It is respectfully asserted that Poltorak is relied upon to provide evidence of the use of three-dimensional printing (¶0083) to create a heat exchanger material in a fractal pattern (¶0069). The reference discloses that the geometry/structure of a fractal in three dimensions that can exhibit infinite surface area in theory and in practice can reach 25 iterations of the fractal. (¶0068) The motivation to do so is found in ¶0069-0070 of Poltorak as discussed in the rejection. Therefore, Poltorak teaches the use of three dimensional printing to create an extremely high surface are to volume ratio fractal material for a heat exchanger is possible and one of ordinary skill would be motivated to do so. Poltorak is not relied upon to teach “infinite surface area” as this is not currently claimed by the applicant.
Applicant argues that “the Office has not sufficiently explained how Chauhan could be combined with Poltorak”.
It is respectfully asserted that this argument does not correspond with the rejection as presented 07/09/2025 in sections 12-18. Chauhan is not indicated as being modified by Poltorak or that Poltorak is being modified to use “the sintering process of Chauhan” as argued.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure can be found on the PTO-892 Notice of references cited form.
Document
Date
Description
US20190021186A1
2018-07-17
¶0053 teaches the use of a fractal pattern for a heat sink. ¶0103 teaches the use of additive manufacturing to create the branching elements and increase the surface area of the elements.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Michael W Hotchkiss whose telephone number is (571)272-3854. The examiner can normally be reached Monday-Friday from 0800-1600.
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/MICHAEL W HOTCHKISS/Primary Examiner, Art Unit 3726