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 .
Response to Amendment
The amendment filed 06/01/2026 has been entered. Claims 20, 22 and 24 have been amended. Claims 15-19 remain canceled. Claims 26-27 are newly submitted claims. Accordingly, claims 1-14 and 20-27 remain pending and are the claims addressed and examined below.
Applicant’s amendments to claims 22 and 24 have overcome the claims objections previously set forth in the Office action mailed 04/18/2025. Applicant’s amendments to claim 20 has overcome the 35 USC 112(b) rejection previously set forth in the Office action mailed 04/18/2025.
Response to Arguments and the Declaration Under 37 CFR 1.132
Applicant's arguments filed 06/01/2026 have been fully considered but they are not persuasive. Applicant submits the following arguments:
(i) Section 103 Rejection – Unexpected Results
Applicant asserts that the results of using camphene are not just an incremental improvement but a “surprising” technical effect that a person having ordinary skill in the art would not have predicted. Applicant states this assertion is consistent with paragraph 7 of the Declaration Under 37 CFR 1.132, where Dr. Choe states:
“REDUCTION IN SHRINKAGE: When camphene is used in our invention, the resulting metallic structure showed 3 times less shrinkage. In other words, our printed parts experiences about 3 percent linear shrinkage (which is about 9 percent volumetric shrinkage) while Xu experiences about 10 to 15 percent linear shrinkage (as indicated by the graph in Xu’s figure 33).”
The Examiner respectfully disagrees. The showing of unexpected results must be commensurate in scope with the invention as claimed. See MPEP § 716.02(d); and in this case, the invention as claimed is directed to an apparatus (i.e., an additive three-dimensional (3D) printing head device in claim 1 and a device in claim 6). The material worked upon or the process of using the apparatus (i.e., use of camphene as a solvent) is viewed as recitation of intended use and is given patentable weight only to the extent that structure is added to the claimed apparatus (see MPEP § 2112.01 I and § 2114-2115 for further details).
The Examiner maintains that a person having ordinary skill in the art would have predicted the results of using camphene consistent with Applicant’s invention given the disclosure in Das, as applied in the rejections set forth in the 04/18/2025, where Das discloses the use of solid camphene as the solvent eliminating difficulties associated with binder polymer pyrolysis due to solid camphene being easily sublimed, the sublimation being a gentle solid-vapor transformation that results in no dimensional change (i.e., less shrinkage), and hence there is little or no warping or cracking in the object being formed (Das at [0069], [0070], [0076], [0086], [0087]).
Moreover, the combination of Xu and Das, as applied in the 04/18/2026 rejections, discloses a syringe dispenser comprising an ink comprising a camphene solvent and a metal or metal oxide powder; and it has been held that where the claimed and prior art products are identical or substantially identical in structure or are produced by identical or a substantially identical processes, a prima facie case of either anticipation or obviousness will be considered to have been established over functional limitations that stem from the claimed structure. In re Best, 195 USPQ 430, 433 (CCPA 1977), In re Spada, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). The prima facie case can be rebutted by evidence showing that the prior art products do not necessarily possess the characteristics of the claimed products. In re Best, 195 USPQ 430, 433 (CCPA 1977). See MPEP § 2112.01 (I) and § 2112.01 (II).
As the combination of Xu and Das teaches all of the structural limitations positively recited by the claim, Applicant’s argument is not persuasive.
(ii) Section 103 Rejection – Xu Teaches Away
Applicant alleges Xu specifically aims for room-temperature, low-cost polymer printing to avoid the complexities of metal printing/heating, then adding a temperature controller or switching to a sublimation-based solvent (which requires specific thermal management) is not a “simple substitution”; and a person having ordinary skill in the art would not seek to solve a problem by introducing the exact complexities (heat and metal) that the prior art explicitly sought to avoid.
Applicant states this allegation is consistent with paragraph 11 of the Declaration Under 37 CFR 1.132, where Dr. Choe states:
“Thus, Xu teaches away from temperature control because Xu seeks a “low cost” approach and avoids metals. Xu believes that a combination of a volatile solvent and PLA polymer (or chitosan) can be used to create a 3D-printable metal powder ink with an adequate viscosity. See Xu’s figure 34 (reproduced below). Although this can work, the resolution of print quality achieved by Xu’s method are significantly lower than that produced by the combination of camphene and acetone solution in our invention.”
The Examiner respectfully disagrees. Contrary to Applicant’s argument, Xu discloses a metallic ink for solvent-cast 3D printing, the ink comprising a solution or a gel of a polymer in a volatile solvent, and heat-sinterable metallic particles dispersed in the solution or gel (Xu at [0009]-[0011], [0176]), and consequently does not avoid metals. While Xu remains silent to temperature control, Xu does not teach away - "the prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of these alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed…." In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d 1141, 1146 (Fed. Cir. 2004). See MPEP § 2141.02 (VI).
(iii) Section 103 Rejection – No Motivation to Combine Das and Xu
Applicant argues that while Das mentions camphene, it would not be obvious to try camphene in Xu’s printing process, as the functional role of camphene is entirely different in the recited invention since camphene is used as a sublimating agent to transport metal powder and then vanish via phase change; whereas, in Das, camphene is used in a photo-curable medium. Applicant further argues that a person having ordinary skill in the art looking at Das would see camphene as a component of a light-sensitive resin, not as a sublimating carrier for metallic powders; and there is no reasonable expectation of success in taking a photo-curable solvent and applying it to a metal sublimation process.
Applicant’s position is consistent with paragraphs 16-17 of the Declaration Under 37 CFR 1.132, where Dr. Choe states:
“In particular, camphene sublimates rapidly at room temperature from solid to vapor so that it can be a perfect sublimating carrier for metallic powder for additive manufacturing. In other words, the printed 3D structure can be maintained due to the quick sublimation of camphene at room temperature.
In our invention, camphene transitions directly from solid to gas. Most 3D printing inks in the prior art rely on evaporation (i.e., liquid to gas). Sublimation avoids the liquid phase entirely which prevents common printing failures like "slumping," surface tension issues, or capillary migration of particles.”
The Examiner respectfully disagrees. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
As discussed in the rejections set forth in the 04/18/2025 Office action, and in the rejections below, Xu discloses the solvent in the metallic ink being any volatile solvent capable of forming a gel of the polymer as well as capable of dispersing metallic particles without reacting with the metallic particles (Xu at [0176]), and solvent evaporation beginning as soon as the ink is extruded out of the nozzle (Xu at [0219]); and Das teaches a continuously moving rapid prototyping system and method for the production of three-dimensional objects such as airfoils from photocurable composite materials containing photopolymers, metals, and the like (Das at [0027], [0038]) – Das also teaches a polymer-ceramic/metal matrix being used (Das at [0015], [0045]), where the photopolymerizable matrix is a mixture of camphor with an acrylic monomer, and camphene being selected because solid camphene has a high vapor pressure making it easy to remove by sublimation (Das at [0069], [0070], [0076], [0086], [0087]), such that solid camphene as the solvent eliminates difficulties associated with binder polymer pyrolysis and liquid drying of hydrogels due to solid camphene being easily sublimed, the sublimation being a gentle solid-vapor transformation that results in no dimensional change, and hence there is little or no warping or cracking in the object being formed (Das at [0069], [0070], [0076], [0086], [0087]). The Examiner maintains that one of ordinary skill in the art viewing Xu and Das would recognize the advantages related to camphene as a solvent would be easily transferrable as a solvent in the apparatus of Xu.
The claims are directed towards an apparatus (i.e., an additive three-dimensional printing head device of claim 1 and a device of claim 6). The material worked upon or the process of using the apparatus is viewed as recitation of intended use and is given patentable weight only to the extent that structure is added to the claimed apparatus (see MPEP § 2112.01 I and § 2114-2115 for further details).
It is the Examiner's assessment, absent evidence to the contrary, that the prior art applied would be capable of meeting the recited material worked upon. See MPEP § 2115 " A claim is only limited by positively recited elements. Thus, "[i]nclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims." (quotes and citation omitted). The burden, therefore, shifts to the Applicant to establish that the prior art does not possess the characteristic relied on (see MPEP § 2115) (citation omitted).
(iv) Section 103 Rejection – No Sublimation Phase Change in Cited References
Applicant argues that neither Xu nor Das describes a process where the solvent bypasses the liquid state to preserve the geometry of a metal structure; this specific physical property enables the invention and is not suggested by any combination of the cited art.
Applicant’s position is consistent with paragraph 19 of the Declaration Under 37 CFR 1.132, where Dr. Choe states:
“Xu's technique does NOT go through a sublimation process as Xu uses polymer PLA/DCM solvent. Neither does chitosan as it is another polymer. Most polymers CANNOT go through sublimation process. This is why Xu must intentionally remove PLA/DCM via an additional thermal decomposition process. And this is perhaps why the resolution quality of their 3D-printed parts is relatively poor because the shape cannot be completely maintained during the thermal decomposition of PLA/DCM polymer (versus natural sublimation of camphene in our invention). And for Das, camphene is only used as a photo-curable solvent, as I pointed out above.”
The Examiner respectfully disagrees. Das teaches a continuously moving rapid prototyping system and method for the production of three-dimensional objects such as airfoils from photocurable composite materials containing photopolymers, metals, and the like (Das at [0027], [0038]) – Das also teaches a polymer-ceramic/metal matrix being used (Das at [0015], [0045]), where the photopolymerizable matrix is a mixture of camphor with an acrylic monomer, and camphene being selected because solid camphene has a high vapor pressure making it easy to remove by sublimation (Das at [0069], [0070], [0076], [0086], [0087]), such that solid camphene as the solvent eliminates difficulties associated with binder polymer pyrolysis and liquid drying of hydrogels due to solid camphene being easily sublimed, the sublimation being a gentle solid-vapor transformation that results in no dimensional change, and hence there is little or no warping or cracking in the object being formed (Das at [0069], [0070], [0076], [0086], [0087]). Thus, contrary to Applicant’s argument, Das explicitly discloses the solvent bypassing the liquid state to preserve the geometry of a metal structure.
Additionally, the claims are directed towards an apparatus (i.e., an additive three-dimensional printing head device of claim 1 and a device of claim 6). The material worked upon or the process of using the apparatus is viewed as recitation of intended use and is given patentable weight only to the extent that structure is added to the claimed apparatus (see MPEP § 2112.01 I and § 2114-2115 for further details).
It is the Examiner's assessment, absent evidence to the contrary, that the prior art applied would be capable of meeting the recited material worked upon. See MPEP § 2115 " A claim is only limited by positively recited elements. Thus, "[i]nclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims." (quotes and citation omitted). The burden, therefore, shifts to the Applicant to establish that the prior art does not possess the characteristic relied on (see MPEP § 2115) (citation omitted).
(v) Section 103 Rejection – Synergistic Effect Between Camphene and Acetone
Applicant asserts there is a synergistic effect between camphene and acetone by significantly
decreasing the viscosity of camphene, the addition of acetone decreases the sublimation time of camphene.
Applicant’s assertion is consistent with paragraphs 21-25 of the Declaration Under 37 CFR 1.132, where Dr. Choe states:
“SUBLIMATION EFFICIENCY: More specifically, the interaction between camphene and acetone is not merely additive but synergistic. The reduction in sublimation time by more than 95 percent (from 48 hours to less than 1 hour) is an unexpected result that exceeds any predictable outcome of adding a generic viscosity modifier. This synergy is significant for the commercial viability of the printing process.”
The Examiner respectfully disagrees. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., a synergistic effect between camphene and acetone by significantly decreasing the viscosity of camphene, the addition of acetone decreases the sublimation time of camphene) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
The claims require a viscosity controlling agent comprising acetone (claims 9 and 26-27). Seeing as Xu discloses the use of acetone, and also adding or removing part of the solvent to allow for adjusting the solvent content in the ink to achieve a desired ink viscosity (Xu at [0176], [0203]), it can be concluded that Xu reads on the claimed viscosity controlling agent comprising acetone.
In conclusion, for at least the reasons set forth above, Applicant’s arguments are not found persuasive and the rejections under 35 USC § 103 are maintained.
The Declaration under 37 CFR 1.132 filed 06/01/2026 is insufficient to overcome the rejection of at least claims 1and 6 based upon Xu et al. (US 2019/0054536) and Das et al. (US 2010/0003619) applied under 35 U.S.C. 103 as set forth in the last Office action because: while the declaration was given full consideration with respect to the statements regarding the scope of terms in question, the declarants legal conclusion that the prior art references are not combinable is not entitled to any weight (see MPEP § 716.01.c.II).
Additionally, as addressed in the response to arguments above, the declaration is not commensurate in scope with the claims. The claims are directed towards an apparatus (i.e., an additive three-dimensional printing head device of claim 1 and a device of claim 6). The material worked upon or the process of using the apparatus is viewed as recitation of intended use and is given patentable weight only to the extent that structure is added to the claimed apparatus (see MPEP § 2112.01 I and § 2114-2115 for further details).
It is the Examiner's assessment, absent evidence to the contrary, that the prior art applied would be capable of meeting the recited material worked upon. See MPEP § 2115 " A claim is only limited by positively recited elements. Thus, "[i]nclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims." (quotes and citation omitted). The burden, therefore, shifts to the Applicant to establish that the prior art does not possess the characteristic relied on (see MPEP § 2115) (citation omitted).
As the combination of Xu and Das teaches all of the structural limitations positively recited by the claims, the declaration is insufficient to overcome the previous rejections.
In view of the foregoing, when all the evidence is considered, the totality of the rebuttal evidence of nonobviousness fails to outweigh the evidence of obviousness.
Claim Rejections - 35 USC § 102
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 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.
Claims 1 and 6 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Xu et al. (US 2019/0054536; of record).
As to claim 1: Xu discloses the claimed additive three-dimensional (3D) printing head device (i.e., an extrusion device is used to extrude metallic inks, the device is mounted on the moving head of a computer controlled 3-axis positioning stage, in order to deposit the extruded ink filament layer by layer on a substrate to create 3D structures) (Xu at [0120], [0158], [0190]-[0193], [0258], [0260], FIG. 16A) comprising:
a syringe dispenser comprising an ink (i.e., an extrusion device is used to extrude metallic inks, this device includes a pressure dispensing system, a micronozzle and a syringe barrel that contains the metallic ink; the metallic ink includes heat-sinterable metallic particles in a volatile solvent which evaporates as soon as the ink is extruded out of the nozzle) (Xu at [0120], [0158], [0160]-[0162], [0168]-[0169], [0219], [0258], [0260], FIG. 16A); and
a needle nozzle (i.e., an extrusion device is used to extrude metallic inks, this device includes a pressure dispensing system, a micronozzle and a syringe barrel that contains the metallic ink; the metallic ink includes heat-sinterable metallic particles in a volatile solvent which evaporates as soon as the ink is extruded out of the nozzle) (Xu at [0120], [0158], [0160]-[0162], [0168]-[0169], [0219], [0258], [0260], FIG. 16A).
The claims are directed towards an apparatus (i.e., an additive three-dimensional (3D) printing head device). The material worked upon or the process of using the apparatus is viewed as recitation of intended use and is given patentable weight only to the extent that structure is added to the claimed apparatus (see MPEP § 2112.01 I and § 2114-2115 for further details).
The following claim recitations are being interpreted as the material worked upon or the process of using the apparatus and therefore being viewed as recitations of intended use: an ink comprising a camphene solvent and a metal or metal oxide powder, which can be injected via a needle nozzle and printed additively by sublimation of the camphene solvent; wherein the camphene solvent transitions directly from a solid state to a gaseous state without passing through a liquid state; when in the syringe dispenser, the camphene solvent of the ink is in the solid state; and after being injected through the needle nozzle from the syringe dispenser, the camphene solvent of the ink sublimates to the gaseous state, wherein the additive three-dimensional (3D) printing head produces a metallic three-dimensional structure.
It is the Examiner's assessment, absent evidence to the contrary, that the prior art applied would be capable of meeting the recited functionality. See MPEP 2114 (II) "A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus teaches all the structural limitations of the claim." (quotes and citation omitted). The burden, therefore, shifts to the Applicant to establish that the prior art does not possess the characteristic relied on (see MPEP § 2114(I)) (citation omitted). Similarly, it is the Examiner's assessment, absent evidence to the contrary, that the prior art applied would be capable of meeting the recited material worked upon. See MPEP § 2115 " A claim is only limited by positively recited elements. Thus, "[i]nclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims." (quotes and citation omitted). The burden, therefore, shifts to the Applicant to establish that the prior art does not possess the characteristic relied on (see MPEP § 2115) (citation omitted).
As to claim 6: Xu discloses the claimed device (i.e., an extrusion device is used to extrude metallic inks, the device is mounted on the moving head of a computer controlled 3-axis positioning stage, in order to deposit the extruded ink filament layer by layer on a substrate to create 3D structures) (Xu at [0120], [0158], [0190]-[0193], [0258], [0260], FIG. 16A) comprising:
a dispenser (i.e., an extrusion device is used to extrude metallic inks) comprising an ink reservoir (i.e., syringe barrel that contains the metallic ink) comprising an ink (i.e., the metallic ink includes heat-sinterable metallic particles in a volatile solvent which evaporates as soon as the ink is extruded out of the nozzle) (Xu at [0120], [0158], [0160]-[0162], [0168]-[0169], [0219], [0258], [0260], FIG. 16A);
a nozzle, coupled to the dispenser, wherein the nozzle comprises a tip comprising an opening, through which the ink can pass (i.e., an extrusion device is used to extrude metallic inks, this device includes a micronozzle to deposit the extruded ink filament layer by layer on a substrate to create 3D structures) (Xu at [0120], [0158], [0160]-[0162], [0168]-[0169], [0219], [0258], [0260], FIG. 16A),
the nozzle is removably coupled to the dispenser (i.e., syringes were attached to smooth-flow tapered nozzles) (Xu at [0260], [0297]); and
a base platform, relative to which the nozzle can be positioned by an electronic controller in X, Y, and Z direction (i.e., computer controlled 3-axis positioning stage) (Xu at [0258], [0260], [0297]).
The claims are directed towards an apparatus (i.e., device). The material worked upon or the process of using the apparatus is viewed as recitation of intended use and is given patentable weight only to the extent that structure is added to the claimed apparatus (see MPEP § 2112.01 I and § 2114-2115 for further details).
The following claim recitations are being interpreted as the material worked upon or the process of using the apparatus and therefore being viewed as recitations of intended use: an ink comprising a metal powder or metal oxide powder and a camphene solvent; after passing through the opening, the camphene solvent transitions directly from a solid state to a gaseous state without passing through a liquid state, and when in the ink reservoir, the camphene solvent of the ink is in the solid state; after being injected through the opening of the dispenser, the camphene solvent of the ink sublimates to the gaseous state; and the ink emitted by the nozzle is deposited on a surface of the base or on a previously deposited layer, and each layer of the ink forms a solid layer in the Z direction of a solid metal object being formed by the device, whereby the ink becomes a solid metal or metal oxide material after being emitted by the nozzle and deposited on the base.
It is the Examiner's assessment, absent evidence to the contrary, that the prior art applied would be capable of meeting the recited functionality. See MPEP 2114 (II) "A claim containing a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus teaches all the structural limitations of the claim." (quotes and citation omitted). The burden, therefore, shifts to the Applicant to establish that the prior art does not possess the characteristic relied on (see MPEP § 2114(I)) (citation omitted). Similarly, it is the Examiner's assessment, absent evidence to the contrary, that the prior art applied would be capable of meeting the recited material worked upon. See MPEP § 2115 " A claim is only limited by positively recited elements. Thus, "[i]nclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims." (quotes and citation omitted). The burden, therefore, shifts to the Applicant to establish that the prior art does not possess the characteristic relied on (see MPEP § 2115) (citation omitted).
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.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-2, 4-5 and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Xu et al. (US 2019/0054536; of record) in view of Das et al. (US 2010/0003619; of record).
As to claim 1: Xu discloses the claimed additive three-dimensional (3D) printing head device (i.e., an extrusion device is used to extrude metallic inks, the device is mounted on the moving head of a computer controlled 3-axis positioning stage, in order to deposit the extruded ink filament layer by layer on a substrate to create 3D structures) (Xu at [0120], [0158], [0190]-[0193], [0258], [0260], FIG. 16A) comprising:
a syringe dispenser comprising an ink comprising a solvent and a metal or metal oxide powder, which can be injected via a needle nozzle and printed additively by sublimation of the solvent (i.e., an extrusion device is used to extrude metallic inks, this device includes a pressure dispensing system, a micronozzle and a syringe barrel that contains the metallic ink; the metallic ink includes heat-sinterable metallic particles in a volatile solvent which evaporates as soon as the ink is extruded out of the nozzle) (Xu at [0120], [0158], [0160]-[0162], [0168]-[0169], [0219], [0258], [0260], FIG. 16A),
after being injected through the needle nozzle from the syringe dispenser, the solvent of the ink transitions to the gaseous state (i.e., solvent evaporation begins as soon as the ink is extruded out of the nozzle) (Xu at [0219]), and
wherein the additive three-dimensional (3D) printing head produces a metallic three- dimensional structure (i.e., 3D printing of the metallic inks allows for highly dense metallic structures having complex geometries to be manufactured as well as high-performance metallic parts) (Xu at [0163], [0238]).
Xu discloses the solvent in the metallic ink being any volatile solvent capable of forming a gel of the polymer as well as capable of dispersing metallic particles without reacting with the metallic particles (Xu at [0176]), and solvent evaporation beginning as soon as the ink is extruded out of the nozzle (Xu at [0219]). Though, Xu fails to explicitly disclose the claimed the solvent being a camphene solvent; wherein the camphene solvent transitions directly from a solid state to a gaseous state without passing through a liquid state; and when in the syringe dispenser, the camphene solvent of the ink is in the solid state, and the camphene solvent of the ink sublimates to the gaseous state.
However, Das teaches a continuously moving rapid prototyping system and method for the production of three-dimensional objects such as airfoils from photocurable composite materials containing photopolymers, metals, and the like (Das at [0027], [0038]). Das further teaches a polymer-ceramic/metal matrix being used (Das at [0015], [0045]), where the photopolymerizable matrix is a mixture of camphor with an acrylic monomer (i.e., solid solvent being camphene), formulated so that it is solid at room temperature, but liquid when warmed above 60oC (i.e., when in the syringe dispenser, the camphene solvent of the ink is in the solid state), and camphene being selected because solid camphene has a high vapor pressure making it easy to remove by sublimation (i.e., wherein the camphene solvent transitions directly from a solid state to a gaseous state without passing through a liquid state; and the camphene solvent sublimates to the gaseous state) (Das at [0069], [0070], [0076], [0086], [0087]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to utilize the solid camphene solvent as such is known in the art of additive three-dimensional printing given the discussion of Das above presenting a reasonable expectation of success; and doing so is a simple substitution of one known solvent for another to obtain predictable results, with the added benefit of solid camphene as the solvent eliminates difficulties associated with binder polymer pyrolysis and liquid drying of hydrogels due to solid camphene being easily sublimed, the sublimation being a gentle solid-vapor transformation that results in no dimensional change, and hence there is little or no warping or cracking in the object being formed (Das at [0069], [0070], [0076], [0086], [0087]).
As to claim 2: Xu and Das teach the device of claim 1 above. Xu further discloses the claimed where the syringe dispenser is connected to an air compressor via an air dispenser controller so that pressured air can be controlled and provided for the additive printing of the ink (i.e., loaded syringes were mounted on a pressure dispensing system, HP-7X, EFD; where EFD is an air powered dispenser) (Xu at [0260], [0297]).
As to claim 4: Xu and Das teach the device of claim 1 above. Xu further discloses the claimed where the ink comprises the solvent having a weight percent between about 2 and about 30 (Xu at [0183]). DAS further teaches/obviates the claimed where the ink comprises the camphene solvent (Das at [0069], [0070], [0076], [0086], [0087]), for similar motivation discussed in the rejection of claim 1.
As to claim 5: Xu and Das teach the device of claim 1 above. Xu further discloses the claimed where the ink comprises metal or metal oxide having a weight percent between about 50 and about 96 (Xu at [0164]).
As to claim 26: Xu and Das teach the device of claim 1 above. Xu further discloses the claimed wherein the ink further comprises a viscosity controlling agent comprising acetone (Xu at [0176], [0203]).
Claims 3 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Xu and Das as applied to claim 1 above, and further in view of Rhoads et al. (US 2019/0283319; of record).
As to claim 3: Xu and Das teach the device of claim 1 above. Xu discloses the metallic ink being extruded at room temperature (Xu at [0120], [0258], [0295]) and Das teaches camphene remaining solid at room temperature, but melts just above room temperature (50oC) (Das at [0070], [0076], [0086], [0087]). Though, Xu modified by Das, fails to explicitly disclose the claimed where the temperature of the ink in the syringe dispenser is adjusted by a temperature controller and is maintained at an ambient temperature between about 30 degrees Celsius and about 50 degrees Celsius.
However, Rhoads teaches a method and apparatus for the 3D printing of highly viscous materials (Rhoads at [0002], [0037]). Rhoads further teaches the 3D printing apparatus using duty cycles for controlling temperature rises to prevent excessive heating (Rhoads at [0037]); and a fan being used to keep the temperature rise below 30 degrees Celsius (Rhoads at [0037]), such that the 3D printing temperature is between 0 degrees Celsius and 50 degrees Celsius (Rhoads at [0047]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to incorporate the 3D printing temperature range taught by Rhoads into the device of Xu modified thus far. Rhoads teaches doing so to be advantageous is low temperature 3D printing of highly viscous materials enables low porosity 3D printing (Rhoads at [0025], [0039], [0043]) as well as 3D printing of highly viscous materials at a lower cost and higher resolution (Rhoads at [0009], [0030], [0032]).
As to claim 20: Xu, Das and Rhoads teach the device of claim 3 above. Xu, modified by Das and Rhoads, further read on the claimed wherein at the ambient temperature between about 30 degrees Celsius and about 50 degrees Celsius, the camphene solvent of the ink is in a solid state in the dispenser (Xu at [0120], [0258], [0295]; Das at [0070], [0076], [0086], [0087]; Rhoads at [0037], [0047]), for similar motivation discussed in the rejection of claim 3.
Claims 6-9, 11-14, 21 and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Xu et al. (US 2019/0054536; of record) in view of Das et al. (US 2010/0003619; of record).
As to claim 6: Xu discloses the claimed device (i.e., an extrusion device is used to extrude metallic inks, the device is mounted on the moving head of a computer controlled 3-axis positioning stage, in order to deposit the extruded ink filament layer by layer on a substrate to create 3D structures) (Xu at [0120], [0158], [0190]-[0193], [0258], [0260], FIG. 16A) comprising:
a dispenser (i.e., an extrusion device is used to extrude metallic inks) comprising an ink reservoir (i.e., syringe barrel that contains the metallic ink) comprising an ink comprising a metal powder or metal oxide powder and a solvent (i.e., the metallic ink includes heat-sinterable metallic particles in a volatile solvent which evaporates as soon as the ink is extruded out of the nozzle) (Xu at [0120], [0158], [0160]-[0162], [0168]-[0169], [0219], [0258], [0260], FIG. 16A);
a nozzle, coupled to the dispenser, wherein the nozzle comprises a tip comprising an opening, through which the ink can pass (i.e., an extrusion device is used to extrude metallic inks, this device includes a micronozzle to deposit the extruded ink filament layer by layer on a substrate to create 3D structures) (Xu at [0120], [0158], [0160]-[0162], [0168]-[0169], [0219], [0258], [0260], FIG. 16A),
the nozzle is removably coupled to the dispenser (i.e., syringes were attached to smooth-flow tapered nozzles) (Xu at [0260], [0297]);
after being injected through the opening of the dispenser, the solvent of the ink transitions to the gaseous state (i.e., solvent evaporation begins as soon as the ink is extruded out of the nozzle) (Xu at [0219]); and
a base platform, relative to which the nozzle can be positioned by an electronic controller in X, Y, and Z directions, and the ink emitted by the nozzle is deposited on a surface of the base or on a previously deposited layer (i.e., computer controlled 3-axis positioning stage) (Xu at [0258], [0260], [0297]), and
each layer of the ink forms a solid layer in the Z direction of a solid metal object being formed by the device, whereby the ink becomes a solid metal or metal oxide material after being emitted by the nozzle and deposited on the base (Xu at [0208], [0209], [0219], [0238], [0258]).
Xu discloses the solvent in the metallic ink being any volatile solvent capable of forming a gel of the polymer as well as capable of dispersing metallic particles without reacting with the metallic particles (Xu at [0176]), and solvent evaporation beginning as soon as the ink is extruded out of the nozzle (Xu at [0219]). Though, Xu fails to explicitly disclose the claimed solvent being a camphene solvent; when in the ink reservoir, the camphene solvent of the ink is in the solid state; and after passing through the opening, the camphene solvent transitions directly from a solid state to a gaseous state without passing through a liquid state; and the camphene solvent of the ink sublimates to the gaseous state.
However, Das teaches a continuously moving rapid prototyping system and method for the production of three-dimensional objects such as airfoils from photocurable composite materials containing photopolymers, metals, and the like (Das at [0027], [0038]). Das further teaches a polymer-ceramic/metal matrix being used (Das at [0015], [0045]), where the photopolymerizable matrix is a mixture of camphor with an acrylic monomer (i.e., solid solvent being camphene), formulated so that it is solid at room temperature, but liquid when warmed above 60oC (i.e., when in the syringe dispenser, the camphene solvent of the ink is in the solid state), and camphene being selected because solid camphene has a high vapor pressure making it easy to remove by sublimation (i.e., wherein the camphene solvent transitions directly from a solid state to a gaseous state without passing through a liquid state; and the camphene solvent sublimates to the gaseous state) (Das at [0069], [0070], [0076], [0086], [0087]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to utilize the solid camphene solvent as such is known in the art of additive three-dimensional printing given the discussion of Das above presenting a reasonable expectation of success; and doing so is a simple substitution of one known solvent for another to obtain predictable results, with the added benefit of solid camphene as the solvent eliminates difficulties associated with binder polymer pyrolysis and liquid drying of hydrogels due to solid camphene being easily sublimed, the sublimation being a gentle solid-vapor transformation that results in no dimensional change, and hence there is little or no warping or cracking in the object being formed (Das at [0069], [0070], [0076], [0086], [0087]).
As to claim 7: Xu and Das teach the device of claim 6 above. Xu further discloses the claimed wherein a pressure source is coupled to the dispenser (i.e., the loaded syringes are mounted on a pressure dispensing system) (Xu at [0260], [0297]).
As to claim 8: Xu and Das teach the device of claim 6 above. Xu further discloses the claimed wherein the ink comprises solvent in a range from about 2 percent to about 30 percent and metal or metal oxide powder in a range from about 50 percent to about 96 percent (Xu at [0160]-[0162], [0164], [0183]). Das further teaches the claimed solvent being camphene (Das at [0069], [0070], [0076], [0086], [0087]), for similar motivation discussed in the rejection of claim 6.
As to claim 9: Xu and Das teach the device of claim 8 above. Xu further discloses the claimed wherein the ink comprises a viscosity controlling agent comprising acetone in a range from about 3 percent to about 20 percent (Xu at [0176], [0183], [0203], [0214]).
As to claim 11: Xu and Das teach the device of claim 8 above. Xu further discloses the claimed wherein the ink comprises a binder comprising a polystyrene or polycaprolactone, or a combination, in a range from about 3 percent to about 30 percent (Xu at [0026], [0162], [0164], [0172], [0258], [0259]).
As to claim 12: Xu and Das teach the device of claim 6 above. Xu, modified by Das, further read on the claimed wherein a viscosity of ink is controlled before going into the nozzle, the ink being in a lukewarm state from about 30 degrees Celsius to about 50 degrees Celsius (Xu at [0120], [0203], [0258], [0295]; Das at [0070], [0076], [0086], [0087]), for similar motivation discussed in the rejection of claim 6.
As to claim 13: Xu and Das teach the device of claim 12 above. Xu further discloses the claimed wherein when the ink is emitted out of the nozzle to be used for printing, the ink solidifies and gets deposited on the base platform layer by layer (Xu at [0120], [0219], [0258], [0297]).
As to claim 14: Xu and Das teach the device of claim 13 above. Xu further discloses the claimed device comprising a fan, positioned near the nozzle to facilitate increasing the viscosity of the ink at a time of printing (Xu at [0220], [0295], FIG. 16A).
As to claim 21: Xu and Das teach the device of claim 6 above. Xu, modified by Das, further read on the claimed wherein at an ambient temperature between about 30 degrees Celsius and about 50 degrees Celsius, the camphene solvent of the ink is in a solid state in the dispenser (Xu at [0120], [0258], [0295]; Das at [0070], [0076], [0086], [0087]), for similar motivation discussed in the rejection of claim 6.
As to claim 27: Xu and Das teach the device of claim 6 above. Xu further discloses the claimed wherein the ink further comprises a viscosity controlling agent comprising acetone (Xu at [0176], [0203]).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Xu and Das as applied to claim 8 above, and further in view of Endoh et al. (US 2019/0283129; of record).
As to claim 10: Xu and Das teach the device of claim 8 above. Xu, modified by Das, fails to disclose the claimed wherein the ink comprises a dispersing agent comprising KD-4 in a range from about 0.4 percent to about 10 percent.
However, Endoh teaches a bonding material of a metal paste containing metal particles to sinter the metal therein (Endoh at [0001], [0006], [0008], [0009], [0010], [0016]). Endoh further teaches the bonding material including a dispersant in the amount of 0.01% to 2% by weight and the dispersant being Hypermer KD4 (Endoh at [0009], [0016]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to utilize the bonding material including a dispersant in the amount of 0.01% to 2% by weight and the dispersant being Hypermer KD4, since it has been held to be within the ordinary skill of a worker in the art to select a known material on the basis of its suitability for the intended use. One would have been motivated to utilize KD4 as a dispersant for the purpose of ensuring the metal particles are sufficiently separated and to prevent the metal particles from settling or clumping.
Claims 22-25 are rejected under 35 U.S.C. 103 as being unpatentable over Xu and Das as applied to claim 6 above, and further in view of Martinez et al. (US 2022/0128581).
As to claim 22: Xu and Das teach the device of claim 6 above. Xu further discloses the claimed wherein an axis passes through the nozzle extending in the Z direction (Xu at FIG. 16A).
Moreover, Xu discloses the metallic ink being extruded at room temperature (Xu at [0120], [0258], [0295]) and Das teaches camphene remaining solid at room temperature, but melts just above room temperature (50oC) (Das at [0070], [0076], [0086], [0087]); though, Xu, modified by Das, fails to disclose the claimed temperature controller comprising a heater extends in the Z direction and positioned along the axis between the nozzle and a top of the dispenser.
However, Martinez teaches temperature-controlled unit for receiving, holding and releasing liquid or semi-liquid material for use in additive manufacturing (Martinez at [0001], [0050], [0064], [0065], FIG. 1); the temperature-controlled unit 1 being a temperature-controlled dispensing head 1a, where Martinez defines dispensing head to be a unit that is capable of releasing and/or dispensing and/or depositing and/or printing material onto a printbed in order to make droplets, filaments and/or 3D multi-layered structures in a controlled and precise way, such as the dispensing head being an inkjet driven dispensing head (Martinez at [0017], [0019], [0050], [0053], [0067], FIG. 2).
Additionally, Martinez teaches the temperature-controlled dispensing head 1a extending along the Z direction and including a DC control connected to a Peltier element 3 extending in the Z direction, positioned along the axis between and a top of the dispenser (Martinez at [0065], [0066], [0067], FIG. 2) in order to regulate the temperature up and down about a desired temperature (Martinez at [0013], [0065], [0081]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to utilize the temperature controller comprising a heater extending in the Z direction and positioned along the axis between the nozzle and a top of the dispenser as such is known in the art of additive manufacturing given the discussion of Martinez above presenting a reasonable expectation of success; and doing so is combining prior art elements according to known methods to yield predictable results, with the added benefit of doing so enabling improved temperature regulation over conventional printheads (as recognized by Martinez at [0013], [0065]).
As to claim 23: Xu, Das and Martinez teach the device of claim 22. Martinez further teaches the claimed wherein a fan is positioned below the temperature controller and points toward the nozzle (i.e., first fan 6a) (Martinez at [0068], [0069], FIG. 2), for similar motivation discussed in the rejection of claim 22.
As to claim 24: Xu, Das and Martinez teach the device of claim 22. Martinez further teaches the claimed wherein the top of the dispenser comprises a dispenser port that is coupled via a hose to an air compressor (i.e., the temperature-controlled dispensing head 1a can be an air powered liquid handling and dispensing system that uses air pressure that is outputted by a pump or a similar device and push on a piston or piston-like component that in turn push a fluid in a barrel/reservoir/cartridge/source well out of the nozzle/orifice) (Martinez at [0003], [0045]), for similar motivation discussed in the rejection of claim 22.
As to claim 25: Xu, Das and Martinez teach the device of claim 24. Martinez further teaches the claimed device comprising an air pressure controller, coupled between the dispenser port and the air compressor (Martinez at [0003], [0045], claims 29-31), for similar motivation discussed in the rejection of claim 22.
Conclusion
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/BAILEIGH KATE DARNELL/Examiner, Art Unit 1743
/GALEN H HAUTH/Supervisory Patent Examiner, Art Unit 1743
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