Markforged Inc v. Continuous Composites Inc

1. Case Identification

• Case #: IPR2022-00732
• Patent #: 10,759,109
• Filed: March 24, 2022
• Petitioner(s): Markforged Inc.
• Patent Owner(s): Continuous Composites, Inc.
• Challenged Claims: 1-15

2. Patent Overview

• Title: Method and Apparatus for Continuous Composite Three-Dimensional Printing
• Brief Description: The ’109 patent discloses methods and an apparatus for additive manufacturing where a composite material is extruded. The composite consists of a continuous solid strand (e.g., fiber or wire) encased within a liquid primary material, which is then cured immediately after extrusion to form a hardened object.

3. Grounds for Unpatentability

Ground 1: Claims 1-15 are obvious over Lipsker in view of Ma

• Prior Art Relied Upon: Lipsker (Patent 6,153,034) and Ma (a 2001 dissertation titled "Solid Freeform Fabrication of Continuous Fiber Reinforced Composite Material").
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Lipsker discloses a base apparatus for rapid prototyping that includes an extruder emitting a continuous wire pre-coated with an adhesive (the primary material), a computer-controlled three-dimensional motion system, and a UV lamp for curing the adhesive. Petitioner argued that Ma supplements Lipsker’s teachings by disclosing a "passive material supplying method" where a continuous fiber tow is explicitly pulled from the extruder nozzle. This pulling action is enabled by the movement of the extruder relative to a previously deposited and cured "anchor point." The combination of Lipsker's apparatus with Ma's passive pulling mechanism allegedly renders all limitations of independent claims 1 and 10 obvious. For dependent claims, Ma was cited for disclosing thermoset resins (claim 15).
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Lipsker and Ma because both relate to automated, additive manufacturing of composite objects. Petitioner argued Ma complements Lipsker by providing detailed mechanics on passive material feeding via anchor points—a concept Lipsker uses but does not elaborate on. A POSITA would have been motivated to incorporate Ma’s explicit teachings on pulling a fiber from the nozzle to better understand and implement the system described in Lipsker.
  • Expectation of Success: The combination would predictably yield a working system, as applying Ma's principles to Lipsker’s apparatus would not require substantial changes or undue experimentation.

Ground 2: Claims 1-9 are obvious over Lipsker in view of Wohrl

• Prior Art Relied Upon: Lipsker (Patent 6,153,034) and Wohrl (U.K. Patent Application GB2213793).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground again used Lipsker as the primary reference for an additive manufacturing system. Petitioner contended that Wohrl, which describes a method for manufacturing fiber-reinforced components, provides the missing teachings for key limitations in independent claim 1. Specifically, Wohrl discloses a computer-controlled six-axis robot and gantry system for moving a fiber-laying device. Crucially, Wohrl teaches that a fiber strand is pulled from a drum by a nip roll and that the material is precured to create "fixed points" or anchor points, which facilitate the pulling action during extruder movement.
  • Motivation to Combine: A POSITA would combine these references because Wohrl describes a precursor technology to Lipsker and discloses key details omitted from Lipsker's description, specifically the mechanics of pulling the fiber from the extruder using anchor points. Petitioner argued that a POSITA would look to a foundational reference like Wohrl to improve upon the system in Lipsker. The teachings were asserted to be seamlessly applicable.
  • Expectation of Success: Applying Wohrl's established principles of robotic control and fiber pulling to Lipsker's system would have been a predictable and successful modification.

Ground 3: Claims 10-13 and 15 are obvious over Ma

• Prior Art Relied Upon: Ma (a 2001 dissertation).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Ma, as a single reference, discloses all elements of the challenged claims. Ma describes a computer-automated Composite Layer Manufacturing (CLM) process for building 3-D objects. Its apparatus includes an extruder that receives an unimpregnated fiber tow (continuous strand) and impregnates it with a matrix material (primary material) before emission. Ma also explicitly teaches using a UV beam to cure photocurable epoxy, satisfying the "means...to harden" limitation. Furthermore, Ma discloses the use of thermosetting resins, directly teaching the limitation of claim 15.
• Additional Grounds: Petitioner asserted additional obviousness challenges, including claims 10-14 over Lipsker alone, claims 1-9 over Ma in view of Wohrl, and claims 1-9 over Ma in view of Lipsker. These grounds relied on similar arguments and prior art mappings to those detailed above.

4. Key Claim Construction Positions

• "means configured to cause the primary material to harden" (claims 3 and 10): Petitioner argued this term is a means-plus-function limitation under pre-AIA 35 U.S.C. §112, ¶ 6. The function is causing the primary material to harden, and the corresponding structure disclosed in the ’109 patent is a UV light source (UV light 501) and the light it generates. Petitioner contended that the UV lamps and other curing mechanisms disclosed in Lipsker, Ma, and Wohrl are the same as or structurally equivalent to the structure disclosed in the ’109 patent, thereby satisfying this limitation.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) and the Fintiv factors would be inappropriate. The core arguments were that the parallel district court litigation was in a very early stage, with no trial date set and fact discovery not yet closed. Petitioner asserted there was minimal investment in the court proceeding, and the IPR petition challenges a broader set of claims (1-15) than those asserted in the litigation (1 and 8), weighing against denial. Petitioner also contended that the strong merits of the unpatentability arguments warranted institution.

6. Relief Requested

• Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-15 of the ’109 patent as unpatentable under 35 U.S.C. §103.