Oregon State University

Patent Trials and Appeals Board

Jul 30, 2020

15202436 - (D) (P.T.A.B. Jul. 30, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
15/202,436 07/05/2016 Chih-Hung CHANG 02.P002 (OSU-15-32) 1330
131643 7590 07/30/2020
Green, Howard, & Mughal LLP
5 Centerpointe Dr.
Suite 400
Lake Oswego, OR 97035
EXAMINER
VAN SELL, NATHAN L
ART UNIT PAPER NUMBER
1783
NOTIFICATION DATE DELIVERY MODE
07/30/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
docketing@ghmip.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte CHIH-HUNG CHANG, CHANG-HO CHOI,
and MICHELE DAVID

Appeal 2019-005838
Application 15/202,436
Technology Center 1700
Before LINDA M. GAUDETTE, FRANCISCO C. PRATS, and
LILAN REN, Administrative Patent Judges.
GAUDETTE, Administrative Patent Judge.
DECISION ON APPEAL1
The Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision finally rejecting claims 1–6, 8, 10, and 12–19.3
We AFFIRM.

1 This Decision includes citations to the following documents:
Specification filed July 5, 2016 (“Spec.”); Final Office Action dated
September 13, 2018 (“Final”); Appeal Brief filed March 14, 2019 (“Appeal
Br.”); Examiner’s Answer dated May 30, 2019 (“Ans.”); and Reply Brief
filed July 30, 2019 (“Reply Br.”).
2 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. The Appellant identifies the real party in interest as
Oregon State University. Appeal Br. 3.
3 We have jurisdiction under 35 U.S.C. § 6(b).
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CLAIMED SUBJECT MATTER
The invention relates to design techniques for dissipating ultra-high
heat fluxes in electronic systems. Spec. 2:10–13. According to the
Specification, at the time of the invention, known techniques for enhancing
heat transfer performance included (1) increasing the available heat surface
area by introducing structures such as fins on the surface, (2) increasing
boiling nucleation sites by controlling the surface texture (e.g., roughening
the surface to create pits and cavities), and (3) engineering the chemical
properties of boiling surfaces such as wettability. Id. at 2:17–22. It was also
known that heterogeneous surfaces with dual hydrophobic and hydrophilic
properties enhance the heat transfer in both boiling and condensation
processes as compared to homogeneously hydrophobic or hydrophilic
surfaces. Id. at 3:12–17. The invention utilizes “[h]eterogeneous surfaces to
enhance and/or control bubble nucleation, bubble sites, and bubble
dynamics,” wherein “at least one of the hydrophilic and hydrophobic
materials is a nanostructured material.” Spec. 8:3–4, 9:24–25. An exemplary
embodiment is illustrated in Figure 1B, reproduced below.
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Figure 1B is a cross-sectional view of heterogeneous boiling surface 101.
Spec. 9:1–2. Surface 101 includes hydrophobic material 120 surrounded by
nanostructured hydrophilic material 110, both of which are disposed over
substrate 105. Id. at 9:3–6, 26. Hydrophobic material 120’s top surface is
recessed below hydrophilic material 110’s surfaces to promote vapor traps to
initiate nucleation in hydrophobic recess 130. Id. at 11:12–14. Hydrophilic
material 110’s thickness H1 is significantly greater than hydrophobic
material 120’s thickness T1. Id. at 11:16–18.
Claims 1, 2, and 6, reproduced below, are illustrative of the claimed
subject matter:
1. An apparatus, comprising:
a substrate;
a vapor bubble nucleation site comprising a hydrophobic thin-
film material over a first region of the substrate, the first
region surrounded by a second region of the substrate;
and
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a hydrophilic nanostructured thin-film material over the second
region of the substrate, wherein a top surface of the
hydrophobic material is recessed below a top surface of
the hydrophilic material.
2. The apparatus of claim 1, wherein:
an average thickness of the hydrophobic thin-film material is
less than that of the hydrophilic material.
6. A heat exchanger vessel having a biphilic working
surface including a spatial array of vapor bubble nucleation
sites comprising a hydrophobic material of a first nominal
thickness within a field comprising hydrophilic nanostructured
material of a second nominal thickness, wherein the first
nominal thickness is less than the second nominal thickness.
Appeal Br. 19–20 (Claims Appendix).
REFERENCES
The Examiner relies on the following prior art as evidence of
unpatentability:
Name Reference Date
Rubner US 2010/0224638 A1 Sept. 9, 2010
Hendricks US 2011/0203772 A1 Aug. 25, 2011
Greer US 2012/0181346 A1 July 19, 2012

REJECTIONS
1. Claim 12 is rejected under 35 U.S.C. § 112(d) as being in
improper dependent form.
2. Claim 1 is rejected under 35 U.S.C. § 103 as unpatentable over
Rubner in view of Hendricks. Final Act. 3.
3. Claims 2–5 are rejected under 35 U.S.C. § 103 as unpatentable
over Rubner in view of Hendricks and Greer.
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4. Claims 6, 8, 10, and 12–14 are rejected under 35 U.S.C. § 103
as unpatentable over Rubner in view of Hendricks and Greer.
5. Claims 15–19 are rejected under 35 U.S.C. § 103 as
unpatentable over Rubner in view of Greer.
OPINION
The Appellant’s patentability arguments are limited to claims 2 and 6,
rejected under 35 U.S.C. § 103 as unpatentable over Rubner in view of
Hendricks and Greer. See generally Appeal Br. 12–17. However, we have
considered these arguments to the extent applicable to the rejections of claim
1 over Rubner in view of Hendricks and claims 15–19 over Rubner in view
of Greer.
Rubner discloses forming a super hydrophilic thin film by depositing
a first ionic species layer on a boiler vessel’s metal surface, and then
depositing a second ionic species having a charge opposite to that of the first
ionic species on the surface to produce a bilayer. Rubner ¶ 5. The
depositions are then repeated to form a plurality of bilayers. Id. “The
bilayers are then heated, leaving the second ionic species on the metal
surface to form a superhydrophilic film.” Id. Rubner discloses that a
majority of the first and second ionic species are nanoparticles. Id. ¶ 24.
Rubner further discloses that hydrophobic regions can be patterned on the
superhydrophilic coating. Id. ¶ 31. According to Rubner, “a combination of
hydrophilic and hydrophobic regions on a surface can simultaneously raise
the boiling heat transfer by promoting bubble nucleation at the hydrophobic
sites and also raise the CHF [(critical value of the heat flux)] by inhibiting
formation of a continuous gas film across the surface during boiling.” Id.
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The Examiner found that Rubner discloses the claim 1 apparatus
except for “a top surface of the hydrophobic material [being] recessed below
a top surface of the hydrophilic material” (claim 1). See Final 3.
Hendricks discloses “a heat exchange surface having raised
hydrophilic nanoporous nanostructures disposed upon a substrate adjacent a
central hydrophobic core.” Hendricks ¶ 5. “[T]he raised nanoporous
nanostructures define interconnected voids and pathways within the
nanoporous nanostructures, and have additional surface irregularities
upon the nanostructures themselves.” Id. Hendricks discloses that “the
nanoporous nanostructures include nucleation sites having a hydrophobic
surface portion with a mean pore diameter of about 1 μm, surrounded by
hydrophilic surfaces with nanoscale dimensions that facilitate rapid and
effective fluid transfer and migration to the hydrophobic surface portion.”
Id. ¶ 8.
The Examiner found that Hendricks paragraph 8 describes a
hydrophobic material top surface that is recessed below a hydrophilic
material top surface. Final 4. The Examiner found that the ordinary artisan
would have substituted or combined Hendricks’s nanoporous nanostructures
with Rubner’s hydrophobic and hydrophilic materials as a matter of design
choice, noting that “substituting known equivalents for the same purpose as
recognized in [the] prior art is prima facie obvious” and that “it is prima
facie obvious to select a known material based on its suitability for its
intended use.” Id.
The Appellant argues that the record evidence fails to support the
Examiner’s finding that Rubner, if modified to include Hendricks’s
nanoporous nanostructures, would have resulted in an apparatus in which the
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hydrophobic material top surface is recessed below the hydrophilic material
top surface. Appeal Br. 14. The Appellant contends that Rubner prints
hydrophobic regions “on” a superhydrophilic coating and, therefore, the
hydrophobic material’s top surface is over, not recessed below, the
hydrophilic material’s top surface. Appeal Br. 13. The Appellant argues that
“while Hendricks’[s] 2D spatial arrangement of a ‘central hydrophobic core’
has similarities with the 2D spatial arrangement presently recited, Hendricks
lacks any disclosure that would fairly guide one of ordinary skill to further
arrive at the 3D spatial arrangement recited for the hydrophobic and
hydrophilic portions.” Id. at 14.
The Appellant’s argument is not persuasive because it fails to address
the Examiner’s findings as to what the combined references’ teachings
would have suggested to the ordinary artisan. See Ans. 15–16. The
Examiner’s rejection is based on substituting or combining Hendricks’s
nanoporous nanostructures with Rubner’s hydrophobic and hydrophilic
materials. See Final 4. In the Final Office Action, as well as in the Answer,
the Examiner cited Hendricks paragraph 8 for a teaching that
the nanostructures can further include a hydrophilic surface that
surrounds the hydrophobic surface portion that includes
nanopores that effectively entrain fluids within the nanopores
and transfer the fluids via strong capillary forces to the
nucleation sites where active boiling takes place (i.e., a top
surface of the hydrophobic material is recessed below a top
surface of the hydrophilic material).
Final 4; see also Ans. 16. The Appellant has not explained why Hendricks’s
paragraph 8 disclosure fails to support the Examiner’s finding that
Hendricks describes “a top surface of the hydrophobic material [that] is
recessed below a top surface of the hydrophilic material,” and that
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substituting or combining Hendricks’s nanoporous nanostructures with
Rubner’s hydrophobic and hydrophilic materials likewise would result in an
apparatus having the hydrophobic material’s top surface recessed below the
hydrophilic material’s top surface (Final 4). See, e.g., Appeal Br. 14; Reply
Br. 10–11.
The Examiner relied on Greer for a teaching of a surface comprising
hydrophobic and hydrophilic films, where the thickness of the hydrophobic
film is less than that of the hydrophilic film, as required by claims 2 and 6.
Greer disclose that “[w]ettability of a surface can be altered by depositing
thin films of varying wettability (e.g. a hydrophilic or a hydrophobic film) or
by intentionally increasing its roughness in a controlled fashion through
incorporating nanostructures that promote or minimize a spreading of
water.” Greer ¶ 63. Greer further discloses that “by controlling height,
distance, width, and inclination angle/curvature, resistance of the surface to a
fluid can be controlled to result in different wetting characteristics.” Id. ¶ 67.
Based on Greer’s disclosure and the Examiner’s finding that “one of
ordinary skill in the art would have known that film thickness will affect
certain physical properties of the film like time it takes to possibl[y] erode,
abrasion resistance, and overall strength of the film,” the Examiner
determined that the ordinary artisan would have adjusted the hydrophilic and
hydrophobic films’ thicknesses in Rubner’s apparatus, as modified by
Hendricks, “to optimize the physical properties of the films as well as the
surface wetting characteristics.” Final 6. In the Answer, the Examiner adds
that “if the hydrophilic region is above the hydrophobic region, it would
have made sense to one of ordinary skill in the art that the hydrophobic thin-
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film material has an average thickness of less than that of the hydrophilic
region, since it is recessed.” Ans. 17.
The Appellant argues that Greer’s teaching that “distances, heights,
widths or depths of nanostructures can create various resistances of the
surface to fluid wetting . . . is in the context of a nanostructured film, not in
the context of two different (hydrophobic and hydrophilic) thin films.”
Appeal Br. 15. The Appellant argues that the Examiner did not show that
adjusting relative heights of the films would have been a predictable
solution. Reply Br. 12. We agree with the Examiner that these arguments are
not persuasive because they fail to consider what the ordinary artisan would
have understood from the combined teachings of the references. See Ans.
15.
As discussed above, supra pp. 7–8, the Appellant has not persuasively
explained why the Examiner’s finding that Hendricks discloses a structure in
which the hydrophobic material’s top surface is recessed below the
hydrophilic material’s top surface is erroneous or unreasonable. Greer
teaches that by controlling height of the nanostructures, resistance of the
surface to a fluid can be controlled to result in different wetting
characteristics. Greer ¶ 67. Greer discloses that “a surface having a high
wettability (e.g. a hydrophilic surface) can exhibit increased wettability
(e.g., a superhydrophilic surface) and a surface having a low wettability
(e.g., a hydrophobic surface) can exhibit decreased wettability (e.g.
superhydrophobic) by providing the surface with nanostructures.” Id. ¶ 71.
Thus, the Examiner had a reasonable basis for finding that the ordinary
artisan would have adjusted the heights of the hydrophilic film’s
nanostructures and the hydrophobic film’s nanostructures to achieve the
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predictable result of optimizing their respective wetting characteristics. See
Final 6.
CONCLUSION
In sum, for the reasons discussed above, in the Final Office Action,
and in the Answer, we are not convinced of reversible error in the
Examiner’s conclusion of obviousness as to claims 1–6, 8, 10, and 12–19.
Any arguments made by the Appellant, but not discussed in this Decision,
have been fully addressed by the Examiner and are unpersuasive for the
reasons explained in the Final Office Action and in the Answer.
Accordingly, we sustain all obviousness rejections.
Because the Appellant does not argue the rejection of claim 12 under
35 U.S.C. § 112(d), we summarily sustain this ground of rejection.
DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis  Affirmed Rever
sed
12 112 Improper dependent form 12
1 103 Rubner, Hendricks 1
2–5 103 Rubner, Hendricks, Greer 2–5
6, 8, 10,
12–14
103 Rubner, Hendricks, Greer 6, 8, 10,
12–14

15–19 103 Rubner, Greer 15–19
Overall
Outcome:

1–6, 8,
10, 12–19

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED