Jerrit Yang is a J.D. candidate, 2021 at NYU School of Law.

            In October 2019, the Federal Circuit added to the very confusing mess of § 101 of the U.S. Patent Law system. Under 35 U.S.C. § 101, an inventor may obtain a patent on “any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof.” The judiciary has created certain exceptions to patentability, however, for “laws of nature, natural phenomena, and abstract ideas.” But doesn’t nearly every invention at some level encompass a law of nature, natural phenomena, or abstract idea? Yes and no. Following the seminal decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc.,[1] the Supreme Court set out a two-step test to determine whether an invention is patent eligible: (1) is the claim directed to a law of nature, natural phenomenon, or abstract idea, and (2) if so, does the claim embody an element or combination of elements that is “sufficient to ensure that the patent in practice amounts to significantly more than a patent upon the ineligible concept itself” (aka, does it have an “inventive concept”)? The Federal Circuit has since used this test to invalidate a variety of inventions in the medical diagnostics, chemical, and software fields. Now, it seems that § 101 is clawing its way towards another unsuspecting industry, mechanical devices.

            In American Axle & Manufacturing, Inc. v. Neapco Holdings LLC.,[2] the Federal Circuit ruled that American Axle’s United States Patent No. 7,774, 911 was invalid for covering unpatentable subject matter. The claims were directed towards a method of manufacturing a vehicle driveline propeller shaft with a liner capable of reducing two types of vibrations simultaneously. According to the patent, propeller shafts – which help to transmit rotary power in a vehicle drive line (think the system of axles, shafts, and gears which function to turn the wheels)—are typically subject to three types of vibrations which cause the shaft to make a lot of noise. These three types of vibration are: (1) “bending mode vibration”—wherein energy is transmitted longitudinally along the shaft and causes the shaft to bend at one or more locations; (2) “torsion mode vibration”—wherein energy is transmitted tangentially through the shaft and causes the shaft to twist; and (3) “shell mode vibration”—wherein a standing wave is transmitted circumferentially about the shaft and causes the cross-section of the shaft to deflect or bend along one or more axes. Though it was previously known that changing certain properties of the liner (e.g., mass, stiffness, etc.) could result in reducing either bending, torsion, or shell mode vibration, American Axle claimed that tuning the liner to reduce bending and shell mode vibrations simultaneously constituted a new invention. The District Court and Federal Circuit majority begged to differ, however.

            The Federal Circuit affirmed the District Court’s finding under Mayo step 1, that the claims of the ’911 patent were directed to the utilization of Hooke’s law and other natural laws/phenomena (such as friction damping). Under step 2, the majority reasoned that there was no inventive concept, because the ’911 claims did not disclose “how target frequencies are determined” or “how liners are tuned to attenuate two different vibration modes simultaneously”; in other words, “[w]hat is missing is any physical structure or steps for achieving the claimed result of damping two different types of vibrations.”[3] For support, the majority mentions the Supreme Court cases, Parker v. Flook[4] and Diamond v. Diehr[5]. In Parker v. Flook, the invention, directed to a method of using a formula to calculate and update an alarm limit in a catalytic conversion process, was found ineligible because it lacked an inventive application (use of alarm limits to trigger alarms, repeated recalculation and readjustment, and use of computers for automatic monitoring were well known). The Flook court also found that merely limiting the solution to a specific purpose did not make it patent eligible. In Diamond v. Diehr, the claims, which were directed to a process for manufacturing rubber utilizing the Arrhenius equation to recalculate and set an alarm limit to automatically open a rubber mold, were found patent eligible and the Court reaffirmed the idea that more than “token postsolution activity” is required.[6] The majority noted that the present claims are essentially a “direction to engage in a conventional, unbounded trial-and-error process” and, like the Flook claims, “amount to no more than conventional pre- and post-solution activity” or limiting the use of the natural law to a particular process.[7]

            In a strong dissent, Judge Moore wrote that the majority was not actually concerned with a natural law or its preemption, but instead was conflating § 101 with § 112 enablement. Judge Moore notes that the majority could “not even identify the precise natural law” which the claims were directed to (majority described as “Hooke’s law and possibly other natural laws”)[8], and that the ’911 patent in fact disclosed several inventive concepts (liners not having previously been used to attenuate bending mode vibration, concrete examples of tuned liners, etc.).  Judge Moore’s dissent is a good example of how many view § 101 as largely serving a gatekeeper function and believe that supposed § 101 issues can often be resolved using other areas of patent law, e.g., § 102, § 103, and/ or § 112.

            Looking at the opinions of this case, it is apparent that there is still no uniform methodology for § 101 analysis. Is the majority’s issue with the claims lacking “how” to determine target frequencies or tune the liners really masking a concern with the breadth of the claims (aka preemption)? It is still unclear whether courts factor preemption into step 1 or step 2 of the Mayo test. Could this have been solved under §112 enablement? For example, if § 101 is restricted to merely a gatekeeping function for claims which would preempt use of the natural law, abstract idea, or natural phenomenon, would an enablement analysis using “undue experimentation” and the Wands factors provide cleaner and more predictable guidance to inventors and patent attorneys? Lots of questions still remain in the § 101 discussion, and it is unlikely they will be answered soon as the Supreme Court has accepted no cases on it for its 2020 session, and recent § 101 legislative proposals have been put on hold. For the moment, maybe all we can take from American Axle is that mechanical devices are not safe from § 101, and it may be best to avoid broadly sweeping, results-oriented claiming.


[1] 566 U.S. 66 (2012).

[2] 939 F.3d 1355 (2019).

[3] Id. at 1366-67.

[4] 437 U.S. 584 (1978).

[5] 450 U.S. 175 (1981).

[6] Id. at 191-92.

[7] 939 F.3d, at 1367-68.

[8] Id. at 1369 (quoting Maj. at 1366).