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Home > Nanotechnology Columns > Magda Carvalho PhD, JD > Written Description Requirement in Applications Involving Nanotechnology

Magda Carvalho
Patent Attorney
Patent Law at M. Carvalho

Section 112 of the 1952 Patent Act requires that a patent application contain a Specification. Section 112 ¶ 1, the written description clause, states that the Specification should contain a "written description of the invention and of the manner and process of making and using… to enable a person with ordinary skill in the art to make and use the invention." The line between the written description and enablement requirements seems unclear. However, the Federal Circuit has stated that the written description clause has two separate and distinct requirements: enablement and written description. (1,2) So far this is the law; and the Patent Office follows it.(3,4) Nonetheless, application of the written description clause is "puzzling," and not well settled in the area of nanotechnology. (5) For nanotech inventions, it may even be challenging to provide an adequate disclosure because of their sophistication, unpredictability and immaturity. Adding to the "puzzle" is the controlling precedent that the disclosure required to meet the written description requirement varies with the nature of the invention. (6) Is the concern about the written description justified? Well, the written description requirement is also a defense to an infringement suit that the Specification did "not contain the whole of the truth concerning his invention."(7)

July 29th, 2008

Written Description Requirement in Applications Involving Nanotechnology

The Board of Patent Appeals and Interferences (Board) decisions provide useful guidance on how to effectively argue written description rejections. Patents are essential for the success of the nanotechnology industry. Thus, this is an issue that must be carefully watched. This issue arises in patent prosecution when (a) the claim adds allegedly new matter (8) not supported by the Specification, usually where a claim is added after the filing, i.e., "late claiming;" (b) the inventor "retreats" an embodiment to avoid prior art or other purpose; or (c) the Specification discloses a specific embodiment of the invention but the claim(s) is rather generic.

This column analyzes three appeal cases before the Board, Ex parte Surh et. al., (9) Ex parte Khan et al., (10) and Ex parte Banerjee and Huang.(11) In Surh, the written description did not support a later filed Claim because the new added embodiment had not been described at the time of filing. In Khan, the written description supported the claimed embodiment, although that embodiment had been retreat after filing. In Banerjee and Huang, the written description rejection was reversed because the Examiner had failed to explain the grounds for the rejection. These decisions confirm that: (a) the Patent Office has the initial burden of showing why an artisan would not recognize that a claimed invention was described and also that it must consider the totality of the record; (b) it is not necessary to spell out every detail of the invention; and (c) every part of the application as originally filed is considered part of an application's disclosure.

Section 112: The Written Description

Section 112 ¶ 1 states that "[t]he specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same…" (12 )

The written description and the enablement requirements apply to the Specification. (13) However, they are two distinct requirements on patentability. In 1967, In re Ruschig the court distinguished the written description requirement from the enablement requirement. (14) The court stated that the issue concerning the description requirement is whether the Specification clearly conveys to those skilled in the art the information that the inventors invented the specific compound.(14) Later in 1991, in Vas-Cath Inc. v. Mahurkar the court stated that the purpose of the written description requirement was to ensure that the applicant had in his or her possession the invention as of the filing date of the application. (16,17)

In summary, satisfaction of the written description analysis would depend on the nature of the claimed subject matter and the facts of each case. The written description itself limits the patent's scope regardless of the magnitude of the claim language. It provides support (both enablement and possession) for the claims. The claims define the invention but must be definite within the meaning of § 112. (18)

Ex parte Surh et. al.

In this case the claim was expanded after the original application was filed. What was missing from the Specification was language supporting the new "distance" range so as to show that the inventor had possession of this embodiment at the time of filing.

The invention applied to "electrophoretic/electrochemical" devices made with nanometer-scale metallic components specifically directed to "sensors using nanolaminates."

After filing the original patent application, the inventor added in Claim 11 the embodiment "d comprises a distance of at least 1 μm" (micrometer). The Examiner concluded that the Claim 11 was invalid for failure to meet the written description requirement since the new added embodiment of "at least 1 μm" covered an area outside of that described in the Specification. The distance disclosed in the Specification was only set as high as "millimeters." The inventor argued that the new embodiment was supported by the phrase "a distance in the range of μm to millimeters" which was recited in the Claim 11 as originally filled. On appeal, the Board agreed with the Examiner.

The Board repeated the law articulated in Vas-Cath Inc., v. Mahurbar that the purpose of the written description requirement was to show that the applicant had possession of the claimed invention. In the Board's view "millimeters" was originally recited not to include "at least 1 μm." The Board based its findings in an old 1976 case, In re Wertheim. In this case the court stated that the phrase "at least 1 μm encompasses a distance greater than millimeters…" (19) Besides, the Board found that there was no evidence in the record that "at least 1 μm" would inherently be included in the "millimeters" range.

Ex parte Khan et al.

This case presented two scenarios. In one scenario, the Examiner failed to consider the totality of the record. In the other, the question was of what constitutes new matter. (20)

The patent application focused on metal molybdenum oxide nanoparticles which were claimed by their physical characteristics as being "non-hollow," "cylindrically shaped," "rod-like", "mean length that is greater than the mea diameter." The nanoparticles were also illustrated in Fig. 4 as an image obtained by transmission electron microscopy. Claims 1 and 4-7 were rejected for lack of written description.

With respect to Claims 1 and 4-6, the Examiner asserted the "possibility" that the nanoparticles may not be "non-hollow" as claimed based on other terms used in application. Besides, the image depicted in Fig. 4 could not tell whether the structure of the nanoparticles were "non-hollow." The Examiner argued that, because of these facts the Claims were rejected for lack of written description (Specification did not support the claimed "non-hollow" nanoparticle). The Board disagreed.

The Board pointed out that to conclude that a prima facie case was made, the Examiner must consider the totality of the record; the whole record includes arguments and evidence. Here, the "other" terms relied upon by the Examiner described only the shape of the nanoparticles and not the interior of the nanoparticles. Besides, the Examiner neither considered the method of preparing the nanoparticles nor considered the Appellants' Nesper reference depicting vanadium oxide nanotubes exemplifying a "hollow" structure, although no explanation was given as to why an artisan would have considered vanadium nanotubes as evidence.

The second issue was whether a claim amendment introduced new matter. Claim 7 further limited the nanoparticles to a BET surface area of "a range of about 33-44 m2/g," the Examiner contended that the Specification neither recited "33" nor "33-44." Therefore, the inventors failed to show they were in possession of what they claimed. The inventors had chosen to retreate the ranges at issue after the filing of the original application. However, the Appellants argued that they were in possession of these embodiments because they had actually made nanoparticles with these embodiments at the time of filing. The Board concluded that the Examiner was incorrect on the new matter rejection.

The Board found that the written description established clearly that the inventors were in possession of the invention at the time of filing. The Board pointed out that in establishing that the inventors were in possession of the invention, each case is determined on its own facts from the perspective of what an artisan would have understood the inventor to have invented from what he now claims. The facts showed that the Specification disclosed the method and apparatus to make nanoparticles in the range of "4-44 m2/g. Since ‘33" is included within this range it was "sufficient to describe the narrower claimed range." Thus, the inventors were in possession of the invention.

Ex parte Banerjee and Huang.

This case is an example of when the Examiner fails to explain the grounds for the rejection. (21)

The invention related to a method of affixing an array of microparticles in a series of recesses in a substrate surface and then incubating a suspension of nanoparticles on top of the microparticles.

The Examiner invalidated several claims under § 112, ¶ 1for lack of written description. However, the Examiner did not provide an explanation as to why the Specification did not disclose the Claim's limitations. The Board reversed the rejections.

The Board pointed out that the Examiner has the initial burden of presenting a prima facie case of unpatentability; why an artisan would not recognize that a claimed invention was described. Furthermore, a lack of literal description in the Specification is not sufficient to support a written description rejection. Additionally, the Board pointed out that the inventors had correlated the claim features at issue with portions of the disclosure. This was a case where support for what was claimed had been identified in the Specification but not evaluated by the Examiner.


Satisfaction of the written description requirement depends on the nature and facts of the invention. The recent released USPTO Guidelines (June 2008) on the written description requirement shows that the Patent Office is still dealing with the court's evolving written description doctrine. Thus, inventors and practitioners are left without clarification how they should draft patent applications and satisfy the written description requirement. It is noteworthy to remember the statement of Judge Rader of the U.S. Court of Appeals for the Federal Circuit in Lizardtech, Inc., v. Earth Resource Mapping, Inc., explaining Capon v. Eshhar, "Bring your specifications to the Federal Circuit and we will tell you if they contain sufficient descriptions."(22)


(1) See 35 U.S.C. § 112 (1994); Appendix A.
(2) See in general Ronald B. Hildreth, Patent Law: A Practitioner's Guide, 3rd Edition ( 2006).
(3) Compare MPEP § 2163 (written description) with MPEP § 2164 (enablement).
(4) Revised Guidelines for Examination of Patent Applications Under the 35 U.S.C. 112, P1, "Written Description" Requirement, 66 Fed. Reg. 1099 (Jan. 5, 2001). These guidelines apply to all technologies.
In June 2008 the USPTO release new Guideline material which "have been updated to reflect developments in case law and technology. "Like earlier training materials, these new materials are intended to assist patent examiners in applying the "Guidelines for Examination of Patent Applications Under the 35 U.S.C § 112, first paragraph ‘Written Description' Requirement" that were published at 66 Fed. Reg. 1099 (Jan. 5, 2001), and are now incorporated in the Manual for Patent Examining Procedure."
(5) Lizardtech, Inc. v. Earth Resource Mapping, Inc., 424 F.3d 1336, 76 USPQ2d 1724 (Fed. Cir, 2005). (A dissent by two judges disagreed that current written description case law is clear and consistent, instead terming it "puzzling.")
(6) Capon v. Eshhar v. Dudas, 76 USPQ2d 1078, 1082 (Fed. Cir. 2005) citing Capon v. Eshhar, Interfer. No. 103,887 at 89 (Bd. Pat. App. & Interf., Mar. 26, 2003).
(7) Donald S. Chisum, Chisum on Patents § 7.02 (2000) (citing the Patent Act of April 10, 1790, ch. 7, § 2, 1 Stat. 109).
(8) Section 706.03(o) of the Manual of Patent Examining Procedure (MPEP) addresses rejections based on new matter; it cites 35 U.S.C. § 132 (a) which prohibits addition of new matter.
(9) Ex parte Surh et. al. Appeal No. 2007-0170 (BPAI May 15, 2007).
(10) Ex parte Khan et. al. Appeal No. 2007-2211(BPAI January 30, 2008).
(11) Ex parte Banerjee and Huang. Appeal No. 2008-1902 (BPAI June 30, 2008).
(12) 35 U.S.C. § 112
(13) Several factors are considered in determining whether a disclosure is enabling, including,: (a) the breadth of the claims; (b) the nature of the invention; (c) the state of the prior art; (d) the level of one of ordinary skill; (f) the level of predictability in the art; (g) the amount of direction provided by the inventor; (h) the existence of working examples; and (k) the quantity of experimentation needed to make or use the invention based on the content of the disclosure.
(14) In re Ruschig, 379 F.2d 990 (C.C.P.A. 1967.
(15) In In re Ruschig originally the patentees claimed chemical compounds for use as oral medications to control diabetes. Later, they added claims to an additional compound. The issue before the court was whether the claims to the additional compound were supported by the disclosure in the original application's Specification. The court sided with the Patent Office Board of Appeals. As the court stated the rejection stood because the broad disclosure of a myriad of compounds left others with no guidance in selecting the new added compound as part of the myriad of compounds.
(16) Vas-Cath Inc. v. Mahurkar, 745 F. Supp. 517, 522 (N.D. Ill. 1990).
(17) In re Wertheim, 541 F.2d 257 (C.C.P.A. 1976.
(18) Section 112 ¶ 2, the definiteness requirement mainly addresses the clarity of the claim language.
(19) In re Wertheim, 541 F.2d 257, 263 USPQ 90, 97 (CCPA 1976).
Upon reply by applicant, before repeating any rejection under 35 U.S.C.112, para. 1, for lack of written description, review the basis for the rejection in view of the record as a whole, including amendments, arguments, and any evidence submitted by applicant. If the whole record now demonstrates that the written description requirement is satisfied, do not repeat the rejection in the next Office action. If the record still does not demonstrate that the written description is adequate to support the claim(s), repeat the rejection under 35 U.S.C. 112, para. 1, fully respond to applicant's rebuttal arguments, and properly treat any further showings submitted by applicant in the reply. When a rejection is maintained, any affidavits relevant to the 35 U.S.C. 112, para. 1, written description requirement, must be thoroughly analyzed and discussed in the next Office action. See In re Alton, 76 F.3d 1168, 1176, 37 USPQ2d 1578, 1584 (Fed. Cir. 1996).
In rejecting a claim, the examiner must set forth express findings of fact which support the lack of written description conclusion (see MPEP § 2163 for examination guidelines pertaining to the written description requirement). These findings should:
(A) Identify the claim *>limitation(s)< at issue; and
(B) Establish a prima facie case by providing reasons why a person skilled in the art at the time the application was filed would not have recognized that the inventor was in possession of the invention as claimed in view of the disclosure of the application as filed. A general allegation of "unpredictability in the art" is not a sufficient reason to support a rejection for lack of adequate written description. A simple statement such as "Applicant has not pointed out where the new (or amended) claim is supported, nor does there appear to be a written description of the claim limitation '____' in the application as filed." may be sufficient where the claim is a new or amended claim, the support for the limitation is not apparent, and applicant has not pointed out where the limitation is supported. >See Hyatt v. Dudas, 492 F.3d 1365, 1370, 83 USPQ2d 1373, 1376 (Fed. Cir. 2007) (holding that "[MPEP] § 2163.04 (I)(B) as written is a lawful formulation of the prima facie standard for a lack of written description rejection.")
(22) Lizardtech, Inc., 76 USPQ2d at 7.

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