Detailed Action
This is a Final Office action based on application 17/307/504 filed on May 4, 2021. The application is a CON of application 16/473,640, and its earliest priority claim is to German application DE10-2016-125818.0, filed December 28, 2016.
Claims 1-12 and 15-22 are pending and have been fully considered.
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 28 April 2026 has been entered.
Status of the Rejection
The §103 rejections of record are maintained
New claim 22 is found to contain subject matter which would be allowable if the claim were written in independent form
Claim Objections
Claims 21 and 22 are objected to because of the following informalities:
Each of these claims opens with the recitation:
“The method as set form in claim 1, wherein ...”
(emphasis added). This is thought to be a typographical error intended to read:
“The method as set forth in claim 1, wherein ...”
Appropriate correction is required.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-4 and 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Vecitis et al (US 2012/0234694 A1) in view of Faris (US 6,805,776 B2).
Regarding claim 1, Vecitis teaches a method for the at least temporary separation and/or detection of charged biologically active substances in a liquid by means of electrosorption and/or electrofiltration (abstract, “to reduce at least one contaminant (e.g., organic molecules, ions and/or biological microorganisms) in an aqueous fluid ... aqueous fluid is flowed through a filtration apparatus comprising a porous carbon nanotube filter material at an applied voltage”),
comprising the following steps:
a. providing a polymer membrane (figure 1, filter membrane 108; para [0595]; per para [0680]-[0684] and figure 56A-C, filter membrane 5604 is a composite comprising porous membrane layer 5614 of PVDF and porous electrosorbent layer of carbon nanotubes) and a porous metal electrode layer adjacent thereto (figure 1A, first electrode layer 110; para [0101], “first conducting material 110 ... can be porous and allow an input fluid to penetrate through and contact the porous carbon nanotube filter material 109; para [0103] “first 110 and second 112 conducting materials can be ... metal”);
b. providing a counterelectrode (figure 1, cathode 112; para [0595], in embodiment of figure 1 the cathode is a perforated steel disk spaced apart from the membrane; para [0088] and [0680]-[0684], in the embodiment of figure 56A-C, the counter electrode is carbon nanotube layer 5618 on the obverse of the membrane);
c. applying a voltage between the working electrode coating of the polymer membrane and the counterelectrode, wherein the voltage is applied to the working electrode with a second polarity opposite to the first polarity (per para [0414]-[0428], E. coli bacteria and bacteriophage MS2 virus (negatively charged) are filtered while positive voltage is applied to the first electrode 110);
d. bringing the polymer membrane and the counterelectrode into contact with the liquid, with the contacting being performed such that the liquid generates at least one connection between the polymer membrane and the counterelectrode (para [0027]; [0414]-[0415]);
and e. electroadsorbing the charged biologically active substances to the polymer membrane due to the voltage applied (para [0026]-[0027]; para [0416], “electrochemical enhancement of viral filtration can be explained by ... physicochemical filtration, where the MWNT anode electrochemically acquires a positive charge, resulting in a deposition (attachment) efficiency of about 1”).
Vecitis does not teach the first electrode is a a flat and porous metal coating on the first surface of the polymer membrane.
Faris discloses a capacitive deionization electrode, configured to remove charged contaminants from water by applying an opposite charge to the electrode and thereby adsorb the contaminent to an electrosorbent material layer on the electrode surface (col 1 ln 10-15, “flow through capacitors for removing ionic substances from charged fluids”; col 3 ln 21-37, “electrode 110 is the negative electrode, thus when the ionic fluid is salt water, sodium ions are absorbed or adsorbed by the electrode 110 and chlorine ions are absorbed by the positive electrode 105”).
Faris teaches that a suitable electrode structure for this purpose is a polymer membrane, coated on at least one side with a flat metal coating, with a high surface area sorbent material disposed on the metal coating (col 5 ln 66 - col 6 ln 11). The metal layer in this structure functions as a current distributor, “to provide efficient electrical conductance at the electrode surface” (col 6 ln 5-6).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the electrosorption membrane of Vecitis by implanting the porous first electrode layer 110, on a surface of the polymer membrane, as flat metal coating for distributing current to the high surface area sorbent material as taught in Faris, with the reasonable expectation that such a structure would be effective for distributing electric current to the electrosorbent material. It reasonably follows that the flat metal coating of Faris, applied to the porous polymer filter membrane of Vecitis, would obviously be configured as a flat porous metal coating so that it does not to obstruct the flow of liquid through the membrane. All the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results. The incorporation of a predictable improvement into a known base invention, based on a finding that the prior art contained a comparable device that has been improved in the same way, is prima facie obvious as being part of the ordinary capabilities of one skilled in the art (MPEP 2143(C)).
Regarding claim 2, Vecitis and Faris render obvious the method of claim 1. The steps of providing the metal coated membrane and the counterelectrode (steps a and b) necessarily take place before the step of applying voltage between the membrane and the counterelectrode (step c), and necessarily take place before the step of bringing the polymer membrane and the counter electrode into contact with the liquid (step d). Furthermore, step c necessarily takes place before and/or after step d. Therefore the prior art method that pre-empts claim 1 necessary pre-empts claim 2 as well.
Regarding claim 3, Vecitis and Faris render obvious the method of claim 1. Vecitis further teaches that after steps a to e, or after steps a to d and during step e, the liquid is removed at least partially and/or the liquid is allowed to pass through the membrane at least partially (para [0182]-[0186], liquid is at least partially allowed to pass through the membrane and is removed via an outlet on the other side; figure 1, “input fluid” passes from inlet 104 through membrane 108 to outlet 106 and is discharged as “output fluid”).
Regarding claim 4, Vecitis and Faris render obvious the method of claim 1, and Vecitis further teaches rinsing the membrane after step e, accompanied by a polarity reversal or reduction in the voltage (para [0209]-[0213], [0507]-[0544]). Vecitis teaches that such a rinsing procedure, accompanied by a reduction or reversal of applied voltage, can effective to regenerate a membrane that is fouled, as well as to recover the substances that are accumulated on the membrane / electrode surface (para [0209]-[0213], [0507]-[0544]).
Regarding claims 8-9, Vecitis and Faris render obvious the method of claim 1, and Vecitis teaches that the counterelectrode is formed by a through arrangement of a permeable electrode, wherein the permeable electrode is formed by a metallic mesh (para [0102], “the second conducting material 112 can be permeable to an input fluid, ... the second conducting material 112 can be a mesh”; para [0105], the counter electrode material can be steel) with interposition of an insulating and permeable spacer (para [0033], “FIG. 1D shows ... the perforated stainless steel cathode 112 ... is separated from the anodic titanium ring 110 by the insulating silicone rubber O-ring 114”; alternative embodiment of [0088] and figure 56A-C, the anode and cathode are disposed on opposite sides of the polymer membrane, and the polymer membrane forms an insulating permeable spacer separating the electrodes).
Regarding claim 21, Vecitis and Faris render obvious the method of claim 1, and Vecitis further teaches wherein the counterelectrode is by an additional flat, porous metal coating on a second side that is situated opposite the first side, the metal coatings are isolated from each other by the polymer membrane (para [0099], “In alternative embodiments, the second conducting material 112 can be positioned between the carbon nanotube filter material 108 and the outlet 106”; para [0102], second conducting material 112 can be porous; figure 56A and para [0105]-[0106], the counterelectrode is “second conducting connector 5606” located on the obverse of the polymer membrane), wherein the polymer membrane acts as an insulator between the metal coatings (para [0132], “the polymer used in the porous polymer layer is an electrical insulator or a poor conductor, or any porous polymer that can provide sufficient electrical insulation between the first and the second conducting connectors (electrodes) to prevent a short circuit”)
Claims 5-7 are rejected under 35 U.S.C. 103 as being unpatentable over Vecitis and Faris as applied to claim 1, in further view of Bormann et al (US 5,536,413 A).
Regarding claims 5-7, Vecitis and Faris render obvious the method of claim 1, and Vecitis teaches a "portable filtration apparatus" embodiment in which the liquid is pressed out of a syringe and through the housing through actuation of the syringe (para [0197]; figure 1B). Vecitis also teaches that the conductive-coated filter membrane may be formed as a circular membrane of 47 mm diameter, to fit in a commercially available 47 mm syringe-tip filter housing (para [0365], [0372], [0411], [0595]; figures 1C-1E show the membrane and housing; figure 1B is a photograph showing filter housing is mounted to the tip of a syringe). However, Vecitis does not disclose the hold-up volume of the syringe.
Bormann discloses a filter device which can be attached to a syringe to filter germs out of a parenteral medicine that is passed through the filter by actuation of the syringe (col 3 ln 35-45; figure 7; col 5 ln 42-61). Bormann's filter housing is sized so as to fit circular filter membranes of 47 mm diameter (col 20 ln 15-18). Bormann further teaches that the hold-up volume of their filter housing is preferably small, most preferably less than 2 mL (col 14 ln 26-30), which falls within the claimed range of no more than 10 mL.
Note that the area of a 47 mm filter membrane disc is about 17.35 cm2 (Bormann col 20 ln 17). A hold-up volume of 2 mL (= 2 cm3), divided by a membrane area of 17.35 cm2, is 0.115 cm3 / cm2 = 1.15 mm3 / mm2. Therefore Bormann's disclosed hold-up volume, applied to the membrane used in both Vecitis and Bormann, falls within the claimed range of wherein the area-normalized hold-up volume is no more than 2 mm3 / mm2.
It would have been obvious to a person having ordinary skill in the art at the time of the invention to modify Vecitis’s filter, which is sized to fit a syringe tip and a 47 mm filter paper, by making the filter housing's hold up volume less than 10 mL and less than (2 mm x the metal-coated membrane area), based on Bormann's teaching that such low hold-up volumes are desirable for a 47 mm filter that attaches to a syringe (col 14 ln 26-30).
Claims 10-12 are rejected under 35 U.S.C. 103 as being unpatentable over Vecitis and Faris as applied to claim 1, in further view of Manniso (US 4,720,400 A).
Regarding claims 10-11, Vecitis and Faris render obvious the method of claim 1, but fail to teach wherein the porosity of the polymer membrane with metal coating is reduced by between 1% and 50%, or between 1% and 20%, relative to the initial bubble point pore and/or the mean pore size compared to the uncoated polymer membrane.
Manniso discloses a polymer membrane with metal coating (col 1 ln 10-15) useful as a filtration or electrofiltration membrane (col 7 ln 30-35, col 10 ln 46 - col 11 ln 7). Manniso further teaches that the porosity of the polymer membrane with the metal coating, as measured by initial bubble point pore size, is reduced by about 3.33% (col 8 Table 1, the bubble point pressure of the coated sample A is 60, and the bubble point pressure of the corresponding uncoated sample A1 is 58. The percent reduction in pore size is therefore (1 - 58/60) * 100% = 3.33%), which falls within the claimed ranges of between 1 and 50% (claim 10) and between 1 and 20% (claim 11).
It would have been obvious to a person having ordinary skill in the art at the time of the invention to implement Vecitis’s metal-coated filtration membrane using the polymer filter membrane pore dimensions and metal coating dimensions as disclosed in Manniso, based on Manniso's teaching that their metal-coated filtration membrane material is suitable for electrofiltration membranes (col 10 ln 46 - col 11 ln 7). The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art (see MPEP 2144.07), and it has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art (see MPEP 2144.05(I)).
Regarding claim 12, Vecitis and Faris render obvious the method of claim 1, but do not teach that the thickness of the metal coating is from 5 to 50 nm and the pore size of the uncoated polymer membrane is greater than 0.01 µm.
Manniso discloses a polymer membrane with metal coating (col 1 ln 10-15) useful as a filtration or electrofiltration membrane (col 7 ln 30-35, col 10 ln 46 - col 11 ln 7). Manniso teaches that the thickness of the metal coating is from 1 to 100 nm (col 2 ln 4-9) which encompasses the claimed range of from 5 to 50 nm, and that the pore size of an uncoated polymer membrane is preferably in a range of from 0.01 to 15 µm (col 2 ln 38-39; col 5 ln 51-52; col 6 ln 54-60).
It would have been obvious to a person having ordinary skill in the art at the time of the invention to implement the method of Vecitis and Faris using the dimensions disclosed for Manniso's membrane, which has a pore size range falling in the claimed range and coating thickness range overlapping the claimed range, based on Manniso's teaching that their metal-coated filtration membrane material is suitable for electrofiltration membranes (col 10 ln 46 - col 11 ln 7). The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art (see MPEP 2144.07), and it has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art (see MPEP 2144.05(I)).
Claims 15-20 are rejected under 35 U.S.C. 103 as being unpatentable over Vecitis and Faris, in further view of Witte.
Regarding claim 15, Vecitis teaches a method for determininq at least one concentration of charged biologically active substances in a liquid by means of electrosorption of the charged biologically active substances to a porous polymer membrane or for determining an occupancy of binding sites of the porous polymer membrane being occupied by charged biologically active substances, comprising the following steps:
a. providing a polymer membrane (figure 1, filter membrane 108; para [0595]; per para [0680]-[0684] and figure 56A-C, filter membrane 5604 is a composite comprising porous membrane layer 5614 of PVDF and porous electrosorbent layer of carbon nanotubes) and a porous metal electrode layer adjacent thereto (figure 1A, first electrode layer 110; para [0101], “first conducting material 110 ... can be porous and allow an input fluid to penetrate through and contact the porous carbon nanotube filter material 109; para [0103] “first 110 and second 112 conducting materials can be ... metal”);
b. providing a counterelectrode (figure 1, cathode 112; para [0595], in embodiment of figure 1 the cathode is a perforated steel disk spaced apart from the membrane; para [0088] and [0680]-[0684], in the embodiment of figure 56A-C, the counter electrode is carbon nanotube layer 5618 on the obverse of the membrane);
c. applying a voltage between the metal coating of the polymer membrane and the counterelectrode (per para [0414]-[0428], E. coli bacteria and bacteriophage MS2 virus (negatively charged) are filtered while positive voltage is applied to the electrode);
d. bringing the polymer membrane and the counterelectrode into contact with the liquid, the liquid containing the charged biologically active substances, with the contacting being performed such that the liquid generates at least one connection between the polymer membrane and the counterelectrode (para [0027]; [0414]-[0415]);
e. removing the liquid at least partially or allowing the liquid to pass through the membrane at least partially to filter the charged biologically active substances by electroadsorbing the charged biologically active substances to the porous polymer membrane (para [0182]-[0186], liquid is at least partially allowed to pass through the membrane to filter contaminants from the liquid, and the filtrate is removed via an outlet on the other side; figure 1, “input fluid” passes from inlet 104 through membrane 108 to outlet 106 and is discharged as “output fluid”; para [0026]-[0027]; para [0416], “electrochemical enhancement of viral filtration can be explained by ... physicochemical filtration, where the MWNT anode electrochemically acquires a positive charge, resulting in a deposition (attachment) efficiency of about 1”); and
f. detecting or evaluating a current flow caused by the applied voltage (para [0211], “for characterizing the performance of the electrode in an electrochemical filtration process ... measuring the current flowing through the filtration apparatus”; para [0374], [0413]); wherein the occupancy of the binding sites of the polymer membrane occupied by charged biologically active substances or the at least one concentration of charged biologically active substances in the liquid is related to the detected or evaluated current flow (para [0374], “In FIG. 3A, the instantaneous current of the aqueous solution flowing at 1.5 mL min−1 is plotted as a function of applied voltage and NaCl concentration ... the current increases with increasing electrolyte concentration”, i.e. the detected current is deterministically related to the concentration of charged species in the solution; para [0511]-[0516], the extent to which the electrode surface is occupied by passivating material is monitored based on the detected current, and this is used to determine when electrode regeneration is needed).
Vecitis does not teach the polymer membrane comprises a flat and porous metal coating on at least a first side thereof.
Faris discloses a capacitive deionization electrode, configured to remove charged contaminants from water by applying an opposite charge to the electrode and thereby adsorb the contaminant to an electrosorbent material layer on the electrode surface (col 1 ln 10-15, “flow through capacitors for removing ionic substances from charged fluids”; col 3 ln 21-37, “electrode 110 is the negative electrode, thus when the ionic fluid is salt water, sodium ions are absorbed or adsorbed by the electrode 110 and chlorine ions are absorbed by the positive electrode 105”).
Faris teaches that a suitable electrode structure for this purpose is a polymer membrane, coated on at least one side with a flat metal coating, with a high surface area sorbent material disposed on the metal coating (col 5 ln 66 - col 6 ln 11). The metal layer in this structure functions as a current distributor, “to provide efficient electrical conductance at the electrode surface” (col 6 ln 5-6).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify the electrosorption membrane of Vecitis by incorporating, on a surface of the polymer membrane, a flat metal coating for distributing current to the high surface area sorbent material as taught in Faris, with the reasonable expectation that such a structure would be effective for distributing electric current to the electrosorbent material. It reasonably follows that the flat metal coating of Faris, applied to the porous polymer filter membrane of Vecitis, would obviously be configured as a flat porous metal coating so that it does not to obstruct the flow of liquid through the membrane.
While Vecitis teaches monitoring the current caused by the applied voltage, and using the monitored current to control regeneration (para [0211], [0374], [0413], [0511]-[0516]), and Vecitis also teaches that the electrode current is related to the concentration of charged biologically active substances in the liquid (para [0374]) and to the occupancy of binding sites on the electrode (para [0511]-[0516]), Vecitis does not explicitly teach that the concentration of the fluid or the occupancy of the binding sites is determined based on the detected or evaluated current flow.
Witte is directed to a capacitive deionization device and method which alternates between a deionization mode in which ions are removed from water and electrosorbed onto porous electrodes, and a regeneration mode in which accumulated ions are released from the binding sites of the electrodes (para [0004]-[0010]). Witte's method includes contacting the electrodes with liquid while applying a voltage between electrodes to electrosorb ions from the liquid onto the electrodes (para [0044]-[0046]); detecting or evaluating a current flow caused by the applied voltage (para [0012], [0060]); and determining an occupancy of the sorption electrodes based on the detected current flow (para [0012], "The electrodes themselves may act as voltage, resistivity, or conductivity sensors to monitor how the electrodes have become loaded with ions extracted from passing fluid through the electrodes. In one example, if the current (or voltage) monitor detects that the current (voltage) flowing to the electrodes goes past a certain, predetermined threshold level or falls within a predetermined range, the programmable logic controller can execute an electrode regeneration process"; para [0060]). Witte teaches that this control protocol is an effective way to automatically determine when the electrodes are fully occupied with bound ions and in need of regeneration (para [0012], [0027]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to incorporate, into the electrosorption filtration method of Vecitis, the step of determining a state of occupancy of the electrode binding sites based on the detection of the amount of current passing through the electrodes, as taught in the method of Witte. Such a step could be implemented in a known way (per Witte para [0012] and [0060], Witte uses a programmable controller to compare the measured current to a threshold value), and would provide the predictable advantage of allowing the filtration method to automatically monitor the electrodes and determine when the electrodes are in need of regeneration (Witte [0027]).
Regarding claim 18, Vecitis and Faris render the method of claim 1 obvious, and Vecitis teaches detecting or evaluating a current flow caused by the applied voltage, wherein the occupancy of the binding sites of the polymer membrane or the at least one concentration of charged biologically active substances in the liquid is related to the detected or evaluated current flow (para [0374], “In FIG. 3A, the instantaneous current of the aqueous solution flowing at 1.5 mL min−1 is plotted as a function of applied voltage and NaCl concentration ... the current increases with increasing electrolyte concentration”, i.e. the detected current is deterministically related to the concentration of charged species in the solution; para [0511]-[0516], the extent to which the electrode surface is occupied by passivating material is monitored based on the detected current, and this is used to determine when electrode regeneration is needed). However, while Vecitis teaches monitoring the current caused by the applied voltage, and using the monitored current to control regeneration (para [0211], [0374], [0413], [0511]-[0516]), and Vecitis also teaches that the electrode current is related to the concentration of charged biologically active substances in the liquid (para [0374]) and to the occupancy of binding sites on the electrode (para [0511]-[0516]), Vecitis does not explicitly teach that the concentration of the fluid or the occupancy of the binding sites is determined based on the detected or evaluated current flow.
Witte is directed to a capacitive deionization device and method which alternates between a deionization mode in which ions are removed from water and electrosorbed onto porous electrodes, and a regeneration mode in which accumulated ions are released from the binding sites of the electrodes (para [0004]-[0010]). Witte's method includes contacting the electrodes with liquid while applying a voltage between electrodes to electrosorb ions from the liquid onto the electrodes (para [0044]-[0046]); detecting or evaluating a current flow caused by the applied voltage (para [0012], [0060]); and determining an occupancy of the sorption electrodes based on the detected current flow (para [0012], "The electrodes themselves may act as voltage, resistivity, or conductivity sensors to monitor how the electrodes have become loaded with ions extracted from passing fluid through the electrodes. In one example, if the current (or voltage) monitor detects that the current (voltage) flowing to the electrodes goes past a certain, predetermined threshold level or falls within a predetermined range, the programmable logic controller can execute an electrode regeneration process"; para [0060]). Witte teaches that this control protocol is an effective way to automatically determine when the electrodes are fully occupied with bound ions and in need of regeneration (para [0012], [0027]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to incorporate, into the electrosorption filtration method of Vecitis, the step of determining a state of occupancy of the electrode binding sites based on the detection of the amount of current passing through the electrodes, as taught in the method of Witte. Such a step could be implemented in a known way (per Witte para [0012] and [0060], Witte uses a programmable controller to compare the measured current to a threshold value), and would provide the predictable advantage of allowing the filtration method to automatically monitor the electrodes and determine when the electrodes are in need of regeneration (Witte [0027]).
Regarding claims 16 and 19, Vecitis and Faris in view of Witte render obvious the methods of claim 15 and 18 respectively, and Witte further teaches that the current flow caused by the applied voltage is evaluated with regard to falling below a limit or exceeding a positive or negative rate of change (para [0012], "if the current (or voltage) monitor detects that the current (voltage) flowing to the electrodes goes past a certain, predetermined threshold level or falls within a predetermined range, the programmable logic controller can execute an electrode regeneration process to regenerate the electrodes").
Regarding claims 17 and 20, Vecitis and Faris in view of Witte render obvious the methods of claim 15 and 18 respectively. Witte further teaches that, in the event the current flow or another measured system parameter undershoots or overshoots a reference value, the system can respond by shutting down and/or by triggering an alarm to notify a technician to address the problem (para [0075], "a series of diagnostics of the apparatus can be performed. ... In another example, the voltage and current supplied to the electrodes 150 can also be diagnosed. If a constant current is supplied and for some reason the voltage exceeds a preset limit, the operation may be suspended. ... status information/condition ... can be stored in the controller 100 at the time that the voltage exceeded the limit so that cause of the abnormality can be determined later on. In another example of diagnostics, if the controller 100 instructs to output fluid and there is still a zero reading on the outlet fluid sensor 320, that may trigger an alarm to alert a technician to address the problem"). Although Witte says that current flow is one of the parameters that is evaluated for overshoot/undershoot to determine that an abnormal operating condition is present (para [0075]), and also says that an alarm is triggered in the event of abnormal operation operating condition (para [0075]), Witte does not specifically say that the alarm is triggered in the event of a current flow overshoot/undershoot. However, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to trigger the alarm in the event of a current overshoot/undershoot, based on Witte's teachings that a current overshoot/undershoot indicates abnormal operation and an alarm should be triggered in the event of abnormal operation. The claimed limitations are obvious because all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results [MPEP 2143(A)].
Allowable Subject Matter
Claim 22 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter:
Claim 22 distinguishes over prior art by the recitation that the polymer membrane, to which the ionic species is adsorbed, the polymer membrane consists of one or more of polysulfone, polypropylene, polyethersulfone, polyetherimide, polyacrylonitrile, polycarbonate, polyethylene terephthalate, polyvinylidene fluoride, polytetrafluoroethylene or cellulose. Taken together with the limitations of claim 1, this claim language requires an electroadsorption method that differs from prior art methods in ways that would not have been obvious prior to their disclosure in this application.
As noted in Applicant’s arguments, (see Remarks filed 28 April 2026), Claim 1 requires the electrically conductive metal layer to be coated onto the exterior face of the polymer membrane, but also specifically requires that ionic species are adsorbed to the polymer membrane rather than to a different material layer disposed on the polymer membrane. Claim 22, by reciting that the polymer membrane consists of a polymer, limits the claim interpretation to one in which the polymer membrane that electrosorbs the ionic species does not include fillers, absorbent materials such as porous carbon, or the metal coating itself. Claim 22 is thereby distinguished from the prior art, because the closest prior art works electrosorb ions onto the porous metal coating, or they incorporate into the polymer membrane a sorbent material (e.g. a porous carbon) and electrosorb ions onto that sorbent.
Representative works of prior art are discussed below:
Vecitis, as discussed above with respect to claims 1 and 15, discloses a method of electroadsorbing ions to a membrane, where the membrane is a multilayer comprising one or more porous layers of a polymer such as polyvinylidene fluoride (PVDF; see para [0133]-[0141], [0667]-[0677]), and one or more layers of carbon nanotubes (CNTs; para [0144]-[0153]). Vecitis teaches that the CNTs are electrically biased to electroadsorb species from solution (para [0416], [0614]-[0615]) and adsorption takes place at the CNT surface (para [0377]).
If Vecitis’s polymer-CNT composite membrane is interpreted as corresponding to the claimed polymer membrane of claim 1, then Vecitis fails to read on claim 22 because Vecitis’s membrane comprises a constituent that is excluded from claim 22. If just the polymer backing layer of Vecitis’s composite is interpreted as corresponding to a polymer membrane, Vecitis would fail to meet the limitations of claim 1 because Vecitis teaches charged species are electrosorbed to the carbon nanotubes, rather than to the polymer layer backing them. Vecitis therefore does not read against this element of the claim.
Suss et al (Energy & Environmental Science, 5, 9511 (2012)) similarly discloses a method for electrosorption of charge species from solution (pg 9511, “capacitive deionization”), comprising providing a laminate of porous carbon aerogel and a porous polypropylene layer (“HCAM” and “Separator” respectively, in pg 9515 figure 4; pg 9515, “FTE CD cell fabrication”), providing metal electrodes on either side (“Current collector” in pg 9515 figure 4), and applying a voltage of a second polarity to an electrode to electroadsorb ions. However, Suss teaches that ions are adsorbed at the pore structure of the carbon aerogel component, rather than at the polypropylene layer (pg 9518 right column para 2). Suss therefore fails to suggest the subject matter of claim 22 for similar reasons as Vecitis – if the carbon layer and the polypropylene layer taken together are considered to be the polymer membrane, then this is not a membrane consisting of polypropylene. If the polypropylene layer alone is considered to correspond to the polymer membrane, then Suss does not teach a method in which the polymer membrane is the spot where electroadsorption takes place.
Branchick (US 4,399,020 A) discloses a membrane comprising of reticulate polymer foam and an electrolessly deposited metal coating (“reticulate metallized organic polymer foam cathodes 17” (col 4 ln 44-45) as illustrated in figures 1 and 14; their preparation is described at col 9 ln 37 – col 10 ln 63). Branchick teaches the polymer may be polypropylene as recited in claim 23 (col 6 ln 5-19). Branchick further teaches a method of electrosorption comprising flowing, through the metal-coated polymer foam, a solution comprising cationic species, and electrically biasing the metal coating with a negative polarity to absorb cations from the solution (col 11 ln 65 – col 12 ln 45).
Branchick’s method does not read on the claimed method, because Branchick absorbs the cationic species onto the porous metal coating (col 13 ln 46-48, “The metal cation, Cu2+, was electrochemically plated out as a neutral metal onto the cathode”), rather than onto the polymer. There is not an obvious modification that could be made to Branchick’s method to result in the cation adsorbing onto the polymer rather than onto the metal.
Muralidhara (US 5,043,048 A), as discussed in the Office Action of 8/29/2024, discloses a method of electrofiltration comprising steps of:
a.) providing a polymer membrane with a flat and porous metal coating at least on a first side of the polymer membrane (figure 3-4 and col 3 ln 44-68, filtration device comprises a filter membrane 301 having a first electrode material 302A integrally formed on it), wherein the polymer membrane material may be polysulfone (col 6 ln 11-14);
b.) providing a counterelectrode (in the embodiment of figure 3, the counterelectrode is located on the opposite side of the membrane 301; in alternate embodiment of figure 4, the counterelectrode 402B is located in the filtrate chamber 305);
c.) applying a voltage between the metal coating of the polymer membrane and the counterelectrode (col 6 ln 21-25, voltage of from 1.5 to 100 V is applied while filtering);
d.) bringing the polymer membrane and the counterelectrode into contact with the liquid, with the contacting being performed such that the liquid generates at least one connection between the polymer membrane and the counterelectrode (col 6 ln 25-27, a current is passed between electrodes while filtering fluid through the membrane, clearly implying that liquid forms a path of electrical connection between electrodes).
However, Muralidhara is specifically applying, to the metal coating of the polymer membrane, a voltage of the same polarity as the charged biologically active substance, for the purpose of repelling the biologically active substance and preventing fouling of the membrane (col 3 ln 24-64). The application of an opposite polarity to the metal coating, to intentionally electroadsorb the biologically active substances, would run counter Muralidhara’s principle of operation. Moreover, even if this were done, there is no reason to expect that the charged substances would adsorb to the polymer membrane rather than to the metal coating as required by the claimed method.
The subject matter of Claim 22 is therefore not suggested in the pertinent prior art.
Response to Arguments
Applicant’s arguments, see Remarks filed 4/28/2026, with respect to the rejection of claim 1, have been fully considered but they are not persuasive.
Applicant argues (Remarks pg 3-5) that Examiner's application of the Vecitis reference against the claim is predicated on an unreasonable interpretation of the claim language. Specifically, Examiner has interpreted that the polymer layer and the adjoining carbon nanotube layer can be considered to collectively form a polymer membrane. Applicant argues that this is an unreasonable interpretation, and that, in light of the text of Vecitis, one skilled in the art would consider these to be two separate membranes. Applicant goes on to argue that, since absorption takes place at the CNTs layer but not the polymer layer, and CNTs are not polymers, neither on the CNT layer alone nor the polymer layer alone is a polymer membrane to which ionic species adsorb. Applicant alleges that the claim construction is based on impermissible hindsight.
Examiner respectfully disagrees. During claim examination, we are mandated to adopt the broadest reasonable interpretation consistent with the contents of the disclosure (MPEP 2111). There is no apparent basis in the specification for excluding multilayer structures from the scope of "membrane", nor for requiring that "polymer membrane" must be made exclusively of polymer as opposed to being a combination of polymer and other materials. Claim 22, which does require the polymer membrane to consist exclusively of polymer to the exclusion of carbon sorbents, distinguishes over Vecitis for this reason; but, claim 1 does not.
Applicant also argues (Remarks pg 6-12) that, if Vecitis were modified in view of Faris, the resulting membrane structure would be different than the structure as claimed. Particularly, Applicant points out that there are three places the metal coating could be placed: (A) atop the CNT layer of the membrane, (B) between the CNTs and the polymer layer, or (C) below the polymer layer. Option (B) corresponds to the positioning that Faris discloses, however, this arrangement does not result in a "metal coating ... on a first side of the polymer membrane" as claimed, because the metal coating is in the middle of the bilayer membrane rather than on a side. Options (A) and (C) match the claim language, however, Applicant argues that if either option (A) and (C) were applied to Vecitis, it would render the base device inoperative.
Examiner respectfully disagrees. Option (A), in which the metallic contact is placed on top of the CNT layer, is the arrangement Vecitis themselves use (Vecitis figure 1a, porous metal 110 is layered directly above the CNTs to provide electrical contact thereto). Option (A) can presumed to be operable because it is disclosed in the reference (MPEP 2121(I)).
Conclusion
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/ANDREW KOLTONOW/Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
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