Prosecution Insights
Last updated: April 19, 2026
Application No. 18/878,696

SUPER-TOUGH CELLULOSE AEROGEL FIBER AS WELL AS PREPARATION METHOD AND USE THEREOF

Non-Final OA §101§102§103§112
Filed
Dec 24, 2024
Examiner
MATZEK, MATTHEW D
Art Unit
1786
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Suzhou Institute Of Nano-Tech And Nano-Bionics (Sinano) Chinese Academy Of Sciences
OA Round
1 (Non-Final)
45%
Grant Probability
Moderate
1-2
OA Rounds
4y 0m
To Grant
84%
With Interview

Examiner Intelligence

Grants 45% of resolved cases
45%
Career Allow Rate
319 granted / 702 resolved
-19.6% vs TC avg
Strong +38% interview lift
Without
With
+38.4%
Interview Lift
resolved cases with interview
Typical timeline
4y 0m
Avg Prosecution
48 currently pending
Career history
750
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
54.9%
+14.9% vs TC avg
§102
15.7%
-24.3% vs TC avg
§112
19.4%
-20.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 702 resolved cases

Office Action

§101 §102 §103 §112
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 . Election/Restrictions Applicant's election with traverse of Group I, claims 1–5 and 15–19, drawn to a super-tough cellulose aerogel fiber in the reply filed on 2/8/2026 is acknowledged. The traversal is on the ground(s) that the two groups are directed to a product and a process specially adapted for the manufacture of said product and they share a special technical feature thereby precluding a finding of lack of unity. Additionally, Applicant argues that the shared technical feature of “a degree of an orientation of the three-dimensional multi-level pore network structure in a length direction gradually increases with a proceeding of stretching,” is not provided by the prior art reference. Furthermore, Applicant contends that no serious burden exists for the search and examination of all claims in the application. These arguments are not persuasive. Initially, the Examiner notes that while the two groups of invention may share a special technical feature, they do not make a required contribution over the prior art. As discussed below in the rejection section of this office action, while the prior art may not expressly state the disputed special technical feature, it is reasonable to presume that such a feature is inherently present in the tough, highly-oriented, cellulose aerogel fibers. Also, the Examiner notes that the claimed aerogel fiber and the method of its making belong in different classifications, which create the serious burden causing the lack of unity/restriction between inventions of the instant claims. The requirement is still deemed proper and is therefore made FINAL. Claims 6–14 and 20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected group, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 2/8/2026. Claim Rejections - 35 USC § 101 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. Claim 15 is rejected under 35 U.S.C. 101 because the claimed invention is directed to non-statutory subject matter. The claim(s) does/do not fall within at least one of the four categories of patent eligible subject matter because claim 15 is directed to a method of using the super-tough cellulose aerogel fiber, but fails to include any method steps for its use. 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 1–5 and 15–19 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. Claim 1, from which all other rejected claims depend, requires a super-tough cellulose aerogel fiber, comprising…a multi-level nanofiber structure, however, later in the claim there is a reference to “link points between nanofibers constitute a strength of a fiber body.” The claim is indefinite because the aerogel fiber comprises a nanostructure, not multiple nanofibers. Accordingly, there would be no links between nanofibers. If Applicant intends to claim an aerogel fiber comprising a nanofiber structure that includes a plurality of nanofibers, the claims should be amended to reflect such intent. Claims 4, 16, and 17 are rejected as where applicant acts as his or her own lexicographer to specifically define a term of a claim contrary to its ordinary meaning, the written description must clearly redefine the claim term and set forth the uncommon definition so as to put one reasonably skilled in the art on notice that the applicant intended to so redefine that claim term. Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1357, 52 USPQ2d 1029, 1033 (Fed. Cir. 1999). The term “micropore” in the rejected claims is used to mean “nanopore,” while the accepted meaning is “a pore in the micrometer range.” The term is indefinite because the specification does not clearly redefine the term. Claim Rejections - 35 USC § 102/103 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 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 – 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. Claim(s) 1–3 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 Li et al., “Tough, Highly Oriented, Super Thermal Insulating Regenerated All-Cellulose Sponge-Aerogel Fibers Integrating a Graded Aligned Nanostructure,” hereinafter, “Li.” Li discloses the formation of a wet spun, tough cellulose aerogel fiber, wherein the fiber has a toughness of 26.20 MJ/m3. Li abstract, p. 3520. Cotton pulp was used as raw material in making the cellulose polymer used in the aerogel fibers. Id. at 3518. The cellulose polymer is crosslinked and forms a fiber in-situ and self-assembled, with a three-dimensional, multi-level pore structure, wherein the pores are largest at a surface of the fiber and decrease in size towards the interior core of the fiber. Id. abstract, Fig. 1a. The fiber has an average pore size of 34 nm in its core. Id. at 3521. The fibers are for use in textiles. Id. abstract. Li fails to teach that when being stretched by an external force, the pore structure in the three-dimensional multi-level pore network structure becomes smaller, a degree of an orientation of the three-dimensional multi-level pore network structure in a length direction gradually increases with a proceeding of stretching, so that strengths of link points between nanofibers constitute a strength of a fiber body to form a cellulose gel fiber with super toughness. Although Li does not explicitly teach the claimed features set forth in the preceding paragraph, it is reasonable to presume that those properties are inherent to Li. Support for said presumption is found in the use of like materials (i.e. super tough cellulose aerogel fiber made in the claimed manner and having the claimed multi-level pore network structure). The burden is upon Applicant to prove otherwise. In re Fitzgerald 205 USPQ 594. In addition, the presently claimed properties above would obviously have been present one the Li product is provided. Note In re Best, 195 USPQ at 433, footnote (CCPA 1977) as to the providing of this rejection made above under 35 USC 102. Claim 3 is rejected as the cellulose polymer is dissolved in a solvent to obtain a molecular-level solution. See Li at 3518. Claim Rejections - 35 USC § 103 Claim(s) 4, 5, and 16–19 are rejected under 35 U.S.C. 103 as being unpatentable over Li. Li teaches that the average pore size in the core of the cellulose aerogel fiber is 34 nm. Li at 3521. As shown in the figures, pore sizes in the cellulose aerogel fiber range 10 nm or less to at least 80 nm. See Li Figure 3b2. As such, Li fails to expressly teach the presence of pores with a size of less than 2 nm. It would have been obvious to one having ordinary skill in the art at the time the invention was made to have made the cellulose aerogel fiber of Li with pores having a size of less than 2 nm, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Although Li does not explicitly teach a maximum tensile strength of 17–30 MPa, an elongation at break of 82–110%, and a toughness of 5–25 MJ/m3, it is reasonable to presume that those properties are inherent to Li. Support for said presumption is found in the use of like materials (i.e. super tough cellulose aerogel fiber made in the claimed manner and having the claimed multi-level pore network structure). The burden is upon Applicant to prove otherwise. In re Fitzgerald 205 USPQ 594. In addition, the presently claimed properties above would obviously have been present one the Li product is provided. Note In re Best, 195 USPQ at 433, footnote (CCPA 1977) as to the providing of this rejection made above under 35 USC 102. Reliance upon inherency is not improper even though rejection is based on Section 103 instead of Section 102. In re Skoner, 517 F.2d 947 (CCPA 1975). Furthermore, it would have been obvious to one having ordinary skill in the art at the time the invention was made to have made the cellulose aerogel fiber of Li with a toughness of 5–25 MJ/m3, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to MATTHEW D MATZEK whose telephone number is (571)272-5732. The examiner can normally be reached M-F 9:30-6. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jennifer Boyd can be reached at 571.272.7783. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /MATTHEW D MATZEK/Primary Examiner, Art Unit 1786
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Prosecution Timeline

Dec 24, 2024
Application Filed
Mar 24, 2026
Non-Final Rejection — §101, §102, §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
45%
Grant Probability
84%
With Interview (+38.4%)
4y 0m
Median Time to Grant
Low
PTA Risk
Based on 702 resolved cases by this examiner. Grant probability derived from career allow rate.

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