Claims 1-20 are pending in the application. Claims 1-20 are rejected.
The rejections over Newman, further in view of Claussen or Pasini have been maintained.
The rejections over Rodgers, further in view of Castro, Claussen or Pasini have been overcome in view of the declaration filed on 7/30/2026.
Rodgers discloses that the biocompatible implant material comprises an open porous metal structure having a substantially uniform porosity, density, pore size, pore shape and pore orientation throughout the volume of the open porous metal structure (paragraph 59). The declaration has demonstrated that the average pore size is not correlated with the pore size distribution such that at least 95% of the pores have the pores being equal to ±10% of the mean pore size ranging from 70 to 700µm.
The rejections over Smith in view of Castro, further in view of Classen or Pasini have been maintained.
The rejection over Petrov has been maintained.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-8, and 10-20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
As recited by claim 1, the matrix forms a pore size gradient with the pore size ranging from 70 to 700 µm. It is unclear whether the pore size gradient is the same as the continuous density gradient or the continuous topological gradient. Appropriate correction is required.
“During examination, after applying the broadest reasonable interpretation to the claim, if the metes and bounds of the claimed invention are not clear, the claim is indefinite and should be rejected. Parkard, 752 F .3d at 1310.”
“If the language of a claim, given its broadest reasonable interpretation, is such that a person of ordinary skill in the relevant art would read it with more than one reasonable interpretation, then a rejection under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C 112, second paragraph is appropriate.” (MPEP 2173.02, I).
The claim looks ambiguous because the matrix having a gradient being a continuous density gradient or a continuous topological gradient renders the scope of the claimed invention unclear because a person having ordinary skill in the art (PHOSITA) could construe the matrix as a batting, a woven or a foam material could have the “gradient being a continuous density gradient or a continuous topological gradient”. However, this is beyond the scope of the claimed invention. In view of Applicant’s disclosure, a lattice structure matrix comprises a beam structure matrix which is graded of relative densities, or topology-graded. Since the structure of the matrix could be interpreted with more than one reasonable interpretation and said more than one reasonable interpretation going beyond the scope of the claimed invention, the claim is rendered indefinite.
As to claim 18, the limitation of a continuous density gradient or a continuous topological gradient has already been addressed in claim 1.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim Rejections - 35 USC § 103
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 2, 4-7, 9-11 and 15 are rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over US 2020/0046512 to Newman et al. (hereinafter “Newman”).
As to claims 1, 10 and 11, Newman discloses that a spinal interbody device (IBD) comprises a solid wall that at least partially defines a boundary of the IBD; and a porous body attached to the solid wall (abstract). The porous body is obtained through selective laser sintering (SLS) or selective laser melting (SLM) of a powder bed of a metal, a metal alloy, a polymer, a ceramic or a composite material (paragraphs 111 and 113).
The porous body is comprised of interconnecting cells, each of the cells including a plurality of struts, which together form a lattice structure (figures 1A, 2C and 2D). The struts of the cells are varied in length and cross-sectional dimension to achieve the desired strain under normal operating condition (paragraph 71). In particular, the length of the struts within the porous body can be increased or decreased to achieve desired porosity (paragraph 72). The porous structure has regions of high porosity where strut lengths of the porous body’s cells are longer than in regions of relatively low porosity (paragraph 72). This allows the porosity or density of the porous body to gradually decrease/increase between regions of minimum and maximum porosities (paragraph 72).
Alternatively, the porous body is optimized to have a uniform strain within a target range throughout the entire volume (paragraph 76, and figure 2C). Indeed, the porous body has struts with uniform length and cross-section dimension to achieve the uniform strain with pores having a regular, repeated shape with an identical pore size throughout the entire volume (figure 2C). Further, the porous body has a pore size of 100 to 700 microns with a mean pore size of 400 to 500 microns and a mean porosity of 55 to 65% (paragraph 70). The porous body having uniform strain in combination with pores having a regular, and repeated shape with an identical pore size of 400 to 500 microns throughout the entire volume pores (figure 2C) indicate that 95% of the pores having the pore size within 10% of the average pore size would inherently be present.
The porous body comprises a plurality of interconnected cells that collectively define a plurality of pores wherein the interconnected cells of the porous body have a geometric shape selected from the group consisting of diamond cubic, single cubic, tetrahedron, dodecahedron and octahedron (paragraph 9; and figures 1A and 1B).
Newman teaches that blood is allowed to penetrate into the pores of the porous structure in view of the configuration of decreasing porosity from the outside toward the center of IBD (paragraph 95). The pores of the porous body are impregnated with blood by capillary. The blood reads on the claimed second material.
As to claim 2, the pores of the porous body are impregnated with blood under a controlled atmosphere and/or pressure (paragraphs 95 and 103).
As to claim 4, a step of optimizing the length and cross-sectional dimension of the strut of the cell is performed using computer aided design before the selective laser printing steps (paragraphs 75 and 76).
As to claims 5 and 15, the porous structure is obtained through SLS or SLM of a powder bed of titanium or its alloys (paragraphs 111 and 113).
As to claim 6, the liquid state temperature of the blood is always less that of titanium porous body.
As to claim 7, the infiltrating blood is an organic compound.
As to claim 9, the cells of the porous structure have a geometric shape selected from the group consisting of diamond cubic, single cubic, tetrahedron, dodecahedron and octahedron (paragraph 9, figures 1B and 2C). The porous structure is thus a lattice structure matrix.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Newman as applied to claim 15 above, further in view of US 6,573,210 to Claussen et al. (hereinafter “Claussen”).
Newman discloses that the porous body is constructed from biocompatible metals, biocompatible polymers, or ceramics (paragraph 113).
Newman does not explicitly disclose the porous body formed from a ceramic/metal composite comprising cermet alumina with 5% aluminum metal incorporated therein.
Claussen, however, discloses an implant constructed from Alumina-Aluminum-Alloyed metal composite wherein the aluminum is present in an amount of 3 vol% to 7 vol% (examples 1-7). In particular, the aluminum is present in an amount of 5 vol% within the claimed range.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to construct an IBD of Newman from a ceramic/metal composite disclosed in Claussen motivated by the desire to obtain excellent wear resistance.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Newman as applied to claim 9 above, further in view of US 2017/0095337 to Pasini et al. (hereinafter “Pasini”).
Newman discloses that the IBD has the porosity increases from the outer layer to the inner layer (paragraph 94). The porosity is graded and so is the density of the IBD. Newman also teaches that the length of each strut in cell may be increased or decreased to achieve the desire porosity (paragraph 70). The struts of the cells are varied in length and cross-sectional dimension to achieve the desired strain under normal operating conditions (paragraph 71). The cells of the porous body have a geometric shape selected from the group consisting of diamond cubic, single cubic, tetrahedron, dodecahedron and octahedron (paragraph 9, figures 1B and 2C).
Newman does not explicitly disclose the diameter of the strut in each cell.
Pasini, however, discloses an implant comprising a porous microstructures comprising a plurality of cells and each comprising a geometric shape selected from the group consisting of diamond cubic, single cubic, tetrahedron, dodecahedron and octahedron (figures 2A-2F). Each cell is made of a plurality of struts with a strut thickness of 200 microns within the claimed range (table 1).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to construct an IBD of Newman having a plurality of cells and each cell comprising a plurality of struts with a strut thickness of 200 microns as taught by Pasini motivated by the desire to effectively achieve the desired strain under normal operating conditions, thereby promoting tissue ingrown within the biocompatible implant material.
Response to Arguments
In the declaration filed on 7/30/2026, Dr. Paul Lohmuller states that the average pore size is not correlated with the pore size distribution such that at least 95% of the pores have the pore size within 10% of the range of 70 to 700 microns. As Newman does not teach the pore size distribution, Newman fails to disclose at least 95% of the pores have the pore size within 10% of the range of 70 to 700 microns.
The examiner respectfully disagrees.
As previously discussed, the porous body of Newman is optimized to have a uniform strain within a target range throughout the entire volume (paragraph 76, and figure 2C). Indeed, the porous body has struts with uniform length and cross-section dimension to achieve the uniform strain with pores having a regular, repeated shape with an identical pore size throughout the entire volume (figure 2C). Further, the porous body has a pore size of 100 to 700 microns with a mean pore size of 400 to 500 microns and a mean porosity of 55 to 65% (paragraph 70).
The porous body having uniform strain in combination with pores having a regular, and repeated shape with an identical pore size of 400 to 500 microns throughout the entire volume pores (figure 2C) indicate that 95% of the pores having the pore size within 10% of the average pore size would inherently be present. Accordingly, the rejection over Newman has been maintained.
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Applicant’s reiterated positions taken with respect to the other rejections: Newman in view of Claussen; and Newman in view Pasini. The examiner’s comments set forth above are equally pertinent in support of these rejections as well.
Claims 1-14, 17 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over US 2006/0198939 to Smith et al. (hereinafter “Smith”) in view of US 2018/0055643 to Castro et al. (hereinafter “Castro”).
As to claims 1, 8, 10 and 11, Smith discloses a porous ceramic composite implant comprising a sintered porous body of a calcium phosphate compound; and a biodegradable polymer coating on the inner and outer surfaces of the porous ceramic body (paragraph 67). The porous ceramic matrix body having interconnected pores is obtained by selective laser sintering (SLS) of a bed of ceramic powder (paragraph 108). The porous ceramic body has a continuous density gradient with the porosity increasing from the outermost regions to the center of the body (paragraphs 53 and 82). The porous ceramic body also has a pore size gradient (paragraph 83). The porous ceramic body has a porosity of about 200 to 600 microns (paragraph 32). The biodegradable polymer is dissolved in a solvent prior to infiltration. The porous ceramic body is placed into a mold; and the biodegradable polymer/solvent is then poured in the mold and allowed to infiltrate the pores and encapsulate the outer surfaces of the porous ceramic body. The mold is placed under reduced pressure, and the solvent is allowed to evaporate until the biodegradable polymer coating of a desired thickness is applied to both the internal and external surfaces of the porous ceramic body (paragraph 87). Smith discloses that the biodegradable polymer is dissolved in a solvent prior to infiltration. The porous ceramic body is placed into a mold; and the biodegradable polymer/solvent is then poured in the mold and allowed to infiltrate the pores and encapsulate the outer surfaces of the porous ceramic body. The mold is placed under reduced pressure, and the solvent is allowed to evaporate until the biodegradable polymer coating of a desired thickness of up to 250 µm is applied to both the internal and external surfaces of the porous ceramic body (paragraph 87). The lower surface of the porous ceramic body is thus immersed in the biodegradable polymer/solvent. The polymer moves through the pores because of surface tension and wetting. As a result, the biodegradable polymer infiltrates the porous ceramic body through capillary wetting in the presence of reduced pressure and solvent evaporation.
Smith discloses that the porous ceramic body is created from a CAD model, the formation of components exhibiting gradient porosities, dense cortical shells and varying geometries is readily achievable (paragraph 109).
Smith does not explicitly disclose a pore size gradient between ta ± 10% and tb ± 10% with ta and tb, each in the range of 70 to 700 microns.
Castro, however, discloses a three-dimensionally (3D) printed tissue engineering scaffold for tissue regeneration obtained using selective laser sintering or selective laser melting (paragraph 70). The scaffold has a gradient pore size increasing from 0 to 50 microns in a first region, through 100 to 200 microns in a second region, to 500 to 1000 microns in a third region (paragraphs 52 and 57). In particular, the scaffold has a gradient pore size increasing from 50 microns in the first region, through 100 microns in the second region, to 500 microns in the third region (paragraphs 52 and 57). The pore size in each region is uniform and within 10% of its mean pore size (figure 1A).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to construct a porous ceramic composite implant of Smith having a gradient pore size as taught by Castro motivated by the desire to promote stem cell development and new tissue growth.
As to claim 2, Smith discloses that the infiltration step is carried out at an ambient temperature such that pharmaceutical agents can be incorporated in the polymer coating (paragraph 89).
As to claim 3, Smith discloses that the solvent is allowed to evaporate until the biodegradable polymer coating of a desired thickness is applied to both the internal and external surfaces of the porous ceramic body (paragraph 87). Hence, the biodegradable polymer is formed by drying the precursor comprising the biodegradable polymer and the solvent.
As to claim 4, Smith discloses that the biodegradable polymer is dissolved in a solvent prior to infiltration. The porous ceramic body is placed into a mold; and the biodegradable polymer/solvent is then poured in the mold and allowed to infiltrate the pores and encapsulate the outer surfaces of the porous ceramic body. The mold is placed under reduced pressure, and the solvent is allowed to evaporate until the biodegradable polymer coating of a desired thickness is applied to both the internal and external surfaces of the porous ceramic body (paragraph 87). Hence, the infiltration step is followed by a drying step.
As to claim 5, Smith discloses that the porous ceramic matrix body having interconnected pores is obtained by selective laser sintering (SLS) of a bed of ceramic powder (paragraph 108).
As to claims 6 and 13, Smith discloses that the melting point of the biodegradable polymer is at least 20% less than the melting point of the ceramic material of the porous matrix body.
As to claims 7 and 17, Smith discloses that the biodegradable polymer is polyester corresponding to an organic compound (paragraph 88).
As to claim 9, Smith discloses that the porous ceramic body is created from a CAD model, the formation of components exhibiting gradient porosities, dense cortical shells and varying geometries is readily achievable (paragraph 109). The porous ceramic body similar to cortical or long bone corresponding to the claimed lattice structure (paragraph 85).
As to claims 12 and 19, Smith discloses that the biodegradable polymer is dissolved in a solvent prior to infiltration. The porous ceramic body is placed into a mold; and the biodegradable polymer/solvent is then poured in the mold and allowed to infiltrate the pores and encapsulate the outer surfaces of the porous ceramic body. The mold is placed under reduced pressure, and the solvent is allowed to evaporate until the biodegradable polymer coating of a desired thickness of up to 250 µm is applied to both the internal and external surfaces of the porous ceramic body (paragraph 87). The lower surface of the porous ceramic body is thus immersed in the biodegradable polymer/solvent. The polymer moves through the pores because of surface tension and wetting. As a result, the biodegradable polymer infiltrates the porous ceramic body through capillary wetting in the presence of a reduced pressure and solvent evaporation.
Smith discloses immersing a lower portion of the porous ceramic body in the biodegradable polymer/solvent. However, Smith does not explicitly disclose immersing only around 1 mm of the lower portion of the porous ceramic body in the biodegradable polymer/solvent.
In the case, where the claimed ranges overlap or touch the range disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257,191 USPQ90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
The claim is not rendered unobvious because discovering the optimum or workable ranges involves only routine skill in the art. Difference in the depth of the porous ceramic body being immersed in the biodegradable polymer/solvent will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating that the depth of the porous ceramic body being immersed in the biodegradable polymer/solvent is critical or provides unexpected results.
Therefore, in the absence of unexpected results, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to immerse only around 1 mm of the lower portion of the porous ceramic body in the biodegradable polymer/solvent, motivated by the desire to create a pathway for capillary forces to draw the biodegradable polymer solution up through the porous ceramic body. As the biodegradable polymer solution seeps into the upper regions, it can effectively fill the pores, ensuring optimal bonding and structural integrity throughout the porous ceramic body. This is in line with In re Aller, 105 USPQ 233 which holds discovering the optimum or workable ranges involves only routine skill in the art.
As to claim 14, Smith discloses that the biodegradable polymer is dissolved in a solvent prior to infiltration. The porous ceramic body is placed into a mold; and the biodegradable polymer/solvent is then poured in the mold and allowed to infiltrate the pores and encapsulate the outer surfaces of the porous ceramic body. The mold is placed under reduced pressure, and the solvent is allowed to evaporate until the biodegradable polymer coating of a desired thickness of up to 250 µm is applied to both the internal and external surfaces of the porous ceramic body (paragraph 87). The lower surface of the porous ceramic body is thus immersed in the biodegradable polymer/solvent. The polymer moves through the pores because of surface tension and wetting. As a result, the biodegradable polymer infiltrates the porous ceramic body through capillary wetting in the presence of reduced pressure and solvent evaporation.
Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Smith as applied to claim 1 above, further in view of Claussen.
Smith discloses that the sintered porous body is made of a ceramic material (paragraph 108).
Smith does not explicitly disclose the sintered porous body formed from a ceramic/metal composite comprising cermet alumina with 5% aluminum metal incorporated therein.
Claussen, however, discloses an implant constructed from Alumina-Aluminum-Alloyed metal composite wherein the aluminum is present in an amount of 3 vol% to 7 vol% (examples 1-7). In particular, the aluminum is present in an amount of 5 vol% within the claimed range.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to construct a sintered porous body of Smith from a ceramic/metal composite disclosed in Claussen motivated by the desire to obtain excellent wear resistance.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Smith as applied to claim 1 above, further in view of Pasini.
Smith discloses that the porous ceramic body has a gradient density with the porosity increasing from the outermost regions to the center of the body (paragraphs 53 and 82).
Smith does not explicitly disclose the porous ceramic body comprising a beam structure matrix wherein a beam diameter ranges from 100 to 300 microns.
Pasini, however, discloses an implant comprising a porous microstructures comprising a plurality of cells and each comprising a geometric shape selected from the group consisting of diamond cubic, single cubic, tetrahedron, dodecahedron and octahedron (figures 2A-2F). Each cell is made of a plurality of struts with a strut thickness of 200 microns within the claimed range (table 1).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to construct a porous ceramic body of Smith having a plurality of cells and each cell comprising a plurality of struts with a strut thickness of 200 microns as taught by Pasini motivated by the desire to effectively achieve the desired strain under normal operating conditions, thereby promoting tissue ingrown within the biocompatible implant material.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Smith as applied to claim 1 above, further in view of Fries et al. (hereinafter “Fries”), “An Analytic solution of Capillary Rise Restrained by Gravity”, Journal of Colloid and Interface Science, 320, 2008, 259-263.
Smith does not explicitly disclose the step of digitally pre-treating the porous ceramic body comprising:
selecting an elementary geometric pattern and a size of the elementary geometric pattern for the ceramic body using a capillary-rise model configured to determine a target infiltration height based on: (i) a density and viscosity of the biodegradable/solvent; (ii) a surface tension and a contact angle between the biodegradable/solvent and the ceramic body, and (iii) characteristic dimensions and a topology of the ceramic body.
Fries, however, discloses an analytic solution for the capillary rise of liquids in a porous medium in terms of height as function of time. The capillary-rise model is configured to determine a target infiltration height based on: (i) a density and viscosity of a fluid; (ii) a surface tension and a contact angle between the fluid and the porous medium, and (iii) characteristic dimensions and a topology of the porous medium (abstract).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use a capillary-rise model disclosed in Fries in the step of digitally pre-treating the porous ceramic body of Smith, motivated by the desire to create a pathway for capillary forces to draw the biodegradable polymer solution up through the porous ceramic body. As the biodegradable polymer solution seeps into the upper regions, it can effectively fill the pores, ensuring optimal bonding and structural integrity throughout the porous ceramic body.
Response to Arguments
Applicant alleges that the claim is not rendered obvious in view of the combined disclosures of Smith and Castro because the combination of the cited references fail to teach the gradient between a size (ta) ± 10% and a size (tb) ± 10% with (ta) and (tb) of about 70 to 700 µm, and (ta) less than (tb), wherein the gradient is a continuous gradient or a continuous topological gradient.
The examiner respectfully disagrees.
Smith discloses that the porous ceramic body has a continuous density gradient with the porosity increasing from the outermost regions to the center of the body (paragraphs 53 and 82). The porous ceramic body also has a pore size gradient (paragraph 83).
Smith does not explicitly disclose a pore size gradient between ta ± 10% and tb ± 10% with ta and tb, each in the range of 70 to 700 microns.
Castro, however, discloses a three-dimensionally (3D) printed tissue engineering scaffold for tissue regeneration obtained using selective laser sintering or selective laser melting (paragraph 70). The scaffold has a gradient pore size increasing from 0 to 50 microns in a first region, through 100 to 200 microns in a second region, to 500 to 1000 microns in a third region (paragraphs 52 and 57). In particular, the scaffold has a gradient pore size increasing from 50 microns in the first region, through 100 microns in the second region, to 500 microns in the third region (paragraphs 52 and 57). The pore size in each region is uniform and within 10% of its mean pore size (figure 1A).
The combined teachings of Smith and Castro result in the porous ceramic body having gradient pore size increasing from 50 microns in the first region, through 100 microns in the second region, to 500 microns in the third region, thereby meeting the claimed requirement.
Applicant further asserts that Smith fails to teach “contacting only a lower portion of the matrix with the second material in liquid form, wherein the second material is drawn into the pores of an upper portion of the matrix by capillary”.
The examiner respectfully disagrees.
Smith discloses that the biodegradable polymer is dissolved in a solvent prior to infiltration. The porous ceramic body is placed into a mold; and the biodegradable polymer/solvent is then poured in the mold and allowed to infiltrate the pores and encapsulate the outer surfaces of the porous ceramic body. The mold is placed under reduced pressure, and the solvent is allowed to evaporate until the biodegradable polymer coating of a desired thickness of up to 250 µm is applied to both the internal and external surfaces of the porous ceramic body (paragraph 87). The lower surface of the porous ceramic body is thus immersed in the biodegradable polymer/solvent. The polymer moves through the pores because of surface tension and wetting. As a result, the biodegradable polymer infiltrates the porous ceramic body through capillary wetting in the presence of reduced pressure and solvent evaporation.
Claims 1, 2, 5-10, 12, 13, 15 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0125894 to Petrov et al. (hereinafter “Petrov”).
As to claims 1, 8, and 10, Petrov discloses a two-phase heat transfer device for dissipating heat from a heat source comprising a main body with a multi-dimensional void network, and a heat transfer media infiltrating the voids by the capillary action (abstract; and paragraph 40). The main body is obtained through SLS of a powder bed of a metal, a metal alloy, a polymer or a composite material (paragraphs 28 and 37). The void network contains a continuous gradient in void size from a first pore size ranging from 20 to 150 microns to a second pore size ranging from 100 to 500 microns (paragraph 26). The pore size distribution shows at least two distinct maxima, one maximum in the first pore size range and the other maximum in the second pore size range (paragraph 26). The void network also contains a continuous gradient in density (paragraph 24). Petrov also discloses the heat transfer media including water, ammonia, methanol, ethanol (paragraph 27) and each of which corresponding to the claimed liquid second material.
Petrov does not explicitly disclose the void network having a continuous gradient in void size from within 10% of a first pore size ranging from 70 to 350 microns to within 10% of a second pore size ranging from 350 to 700 microns.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to construct the main body of Petrov having a void network with a continuous gradient in void size from within 10% of a first pore size ranging from 70 to 350 microns to within 10% of a second pore size ranging from 350 to 700 microns, motivated by the desire to enhance heat dissipation efficiency.
As to claim 2, Petrov discloses that the heat transfer medium is infiltrated into the voids of the main body by the capillary action under a controlled atmosphere (paragraph 40).
As to claim 5, Petrov discloses that the main body is obtained through SLS of a powder bed of a metal or a metal alloy (paragraphs 28 and 37).
As to claims 6 and 13, Petrov discloses that the melting temperature of water (0oC) is at least 20% less than that of the metal or metal alloy (paragraphs 27 and 28).
As to claim 7, Petrov discloses that the heat transfer medium comprises ammonia or ethanol and each of which corresponding to the claimed inorganic or organic compound (paragraph 27).
As to claim 9, Petrov discloses that the main body comprises an ordered quadratic or hexagonal lattice (paragraph 25).
As to claim 12, Petrov discloses that the void network is arranged such that the heat transfer medium flows forward the center of the base layer. The void network is adapted by its 3D shape and by its void size gradient to the cooling needs of the power semiconductor module, which has a higher cooling need in a hot spot region 22 near the center of the base layer (paragraph 54 and figure 1). The flow of heat transfer medium along the path through the main body is based on a variation in capillary action exerted by the multi-dimensional void network in the heat transfer medium along the path (paragraphs 34, 40 and 52). The flow of heat transfer medium along the path through the main body indicates that the heat transfer medium contacts only a lower portion of the void network and infiltrates in the voids of the upper portion of the void network by capillary.
As to claim 15, Petrov discloses that the main body is obtained through SLS of a powder bed of a metal, a metal alloy, a polymer or a composite material (paragraphs 28 and 37).
As to claim 19, Petrov discloses that the void network is arranged such that the heat transfer medium flows forward the center of the base layer. The void network is adapted by its 3D shape and by its void size gradient to the cooling needs of the power semiconductor module, which has a higher cooling need in a hot spot region 22 near the center of the base layer (paragraph 54 and figure 1). The flow of heat transfer medium along the path through the main body is based on a variation in capillary action exerted by the multi-dimensional void network in the heat transfer medium along the path (paragraphs 34, 40 and 52). The flow of heat transfer medium along the path through the main body indicates that the heat transfer medium contacts only a lower portion of the void network and infiltrates in the voids of the upper portion of the void network by capillary. Petrov discloses immersing only the lower portion of the main body with the heat transfer medium. However, Petrov does not disclose immersing only around 1 mm of the lower portion of the main body in the heat transfer medium.
In the case, where the claimed ranges overlap or touch the range disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257,191 USPQ90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
The claim is not rendered unobvious because discovering the optimum or workable ranges involves only routine skill in the art. Difference in the depth of the main body being immersed in the heat transfer medium will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating that the depth of the main body being immersed in the heat transfer medium is critical or provides unexpected results.
Therefore, in the absence of unexpected results, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to immerse only around 1 mm of the lower portion of the main body in the heat transfer medium, motivated by the desire to provide a reliable heat transfer device with an increased heat dissipation for heat source. This is in line with In re Aller, 105 USPQ 233 which holds discovering the optimum or workable ranges involves only routine skill in the art.
Response to Arguments
Applicant alleges that Petrov fails to disclose or suggest at least forming a gradient between as size the gradient between a size (ta) ± 10% and a size (tb) ± 10% with (ta) and (tb) of about 70 to 700 µm, and (ta) less than (tb), wherein the gradient is a continuous gradient or a continuous topological gradient.
The examiner respectfully disagrees.
Petrov discloses that the void network contains a continuous gradient in void size from a first pore size ranging from 20 to 150 microns to a second pore size ranging from 100 to 500 microns (paragraph 26). The pore size distribution shows at least two distinct maxima, one maximum in the first pore size range and the other maximum in the second pore size range (paragraph 26). Petrov also teaches that the void network contains a continuous gradient in density (paragraph 24).
Petrov does not explicitly disclose the void network having a continuous gradient in void size from within 10% of a first pore size ranging from 70 to 350 microns to within 10% of a second pore size ranging from 350 to 700 microns.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to construct the main body of Petrov having a void network with a continuous gradient in void size from within 10% of a first pore size ranging from 70 to 350 microns to within 10% of a second pore size ranging from 350 to 700 microns, motivated by the desire to enhance heat dissipation efficiency.
Applicant argues that Petrov fails to teach “contacting only to lower portion of the matrix with the second material in liquid form, in which the liquid second material is drawn into the pores of an upper portion of the matrix by capillary.”
The examiner respectfully disagrees.
Petrov discloses that the heat transfer medium comprises ammonia or ethanol and each of which corresponding to the claimed inorganic or organic compound (paragraph 27). The void network is arranged such that the heat transfer medium flows forward the center of the base layer. The void network is adapted by its 3D shape and by its void size gradient to the cooling needs of the power semiconductor module, which has a higher cooling need in a hot spot region 22 near the center of the base layer (paragraph 54 and figure 1). The flow of heat transfer medium along the path through the main body is based on a variation in capillary action exerted by the multi-dimensional void network in the heat transfer medium along the path (paragraphs 34, 40 and 52). The flow of heat transfer medium along the path through the main body indicates that the heat transfer medium contacts only a lower portion of the void network and infiltrates in the voids of the upper portion of the void network by capillary.
Accordingly, the rejection over Petrov has been maintained.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 Hai Vo whose telephone number is (571)272-1485. The examiner can normally be reached M-F: 9:00 am - 6:00 pm with every other Friday off.
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/Hai Vo/
Primary Examiner
Art Unit 1788
