Diamond in the Rough: Infringement Theory Foreclosed by Claim Construction Supports $3.2M Fee Award

Thursday, October 1, 2026

The US Court of Appeals for the Federal Circuit affirmed an award of more than $3.2 million in attorneys’ fees and non-taxable expenses, finding no abuse of discretion in the district court’s determination that the patent owner and its exclusive licensee continued to pursue an objectively baseless infringement theory after claim construction and discovery foreclosed their position. Carnegie Institution of Washington v. Fenix Diamonds LLC, Case Nos. 24-1804; -1824 (Fed. Cir. Sept. 17, 2026) (Reyna, Taranto, Stoll, JJ.) (nonprecedential).

Carnegie Institution of Washington and its exclusive licensee, M7D Corporation, sued Fenix Diamonds for infringement of two patents directed to methods for producing lab-grown diamonds using chemical vapor deposition. The asserted claims required growing single-crystal diamonds on a growth surface with only insubstantial non-monocrystalline growth. After claim construction, Fenix produced evidence from its manufacturer, Nouveau Diamonds, showing extensive polycrystalline and nondiamond growth. The district court subsequently granted summary judgment of noninfringement.

After the plaintiffs voluntarily dismissed their appeal following M7D’s financial collapse, the district court found the case exceptional under 35 U.S.C. § 285. It concluded that the plaintiffs’ infringement theory became objectively baseless once they received Nouveau’s evidence – approximately one month before the date from which the court ultimately shifted fees. The district court also exercised its inherent authority to award nontaxable expenses, including expert fees, based on what it viewed as vexatious and unreasonable litigation conduct. Among other things, the district court cited a misleading representation concerning access to a facility and the plaintiffs’ eleventh-hour abandonment of one of the asserted patents. Carnegie appealed.

Carnegie argued that its expert’s infringement theory represented a reasonable application of the district court’s claim construction rather than an attempt to relitigate it. The Federal Circuit disagreed. The district court had expressly construed the disputed “growth surface” limitation as not categorically excluding polycrystalline growth. According to the Federal Circuit, the expert’s attempt to exclude a subset of such growth effectively reintroduced a limitation that the district court had rejected. The district court therefore did not abuse its discretion in concluding that the infringement theory was inconsistent with the governing claim construction.

The Federal Circuit also rejected Carnegie’s challenges to the scope and amount of the award. On causation, the Court explained that once a district court identifies the point at which continued litigation became objectively baseless, it need not tie each subsequent fee to a discrete act of misconduct. The district court could therefore shift all reasonable fees incurred after that point.

The Federal Circuit also affirmed the imposition of joint-and-several liability on Carnegie. Although Carnegie characterized itself as a passive licensor, the Court pointed to its close and intertwined relationship with M7D, including shared counsel, joint litigation filings, and consultation rights under the license agreement. Those circumstances supported holding Carnegie responsible for the fee award along with M7D.

Finally, the Federal Circuit affirmed the denial of Fenix’s request for prejudgment interest. Fenix had not sought prejudgment interest before the district court issued its exceptional-case ruling and, when Fenix later raised the issue, it failed to respond to Carnegie’s waiver argument. The Court therefore agreed that the request had been forfeited.