SHENZHEN TUOZHU TECHNOLOGY CO., LTD. et al. v. Stratasys Inc.

This Inter Partes Review (IPR) proceeding, IPR2025-00321, involves a patent validity challenge brought by SHENZHEN TUOZHU TECHNOLOGY CO., LTD., BAMBULAB LIMITED, SHANGHAI LUNKUO TECHNOLOGY CO. LTD., TUOZHU TECHNOLOGY LIMITED, and BAMBULAB USA, INC. (collectively, "Bambu Lab entities") against Stratasys Inc. Stratasys, an American-Israeli company, is a prominent global manufacturer of 3D printers, software, and materials for polymer additive manufacturing, known for its industrial and professional systems. The petitioners, operating under the "Bambu Lab" brand, are a consumer tech company based in Shenzhen, China, with operations in Shanghai and Austin, Texas, specializing in high-speed, AI and cloud-powered desktop 3D printers that have rapidly gained market share. The IPR stems from a broader patent infringement lawsuit filed by Stratasys against Bambu Lab in the U.S. District Court for the Eastern District of Texas in August 2024, alleging that Bambu Lab's popular 3D printer models, including the X1C, X1E, P1S, P1P, A1, and A1 mini, infringe ten of Stratasys's patents covering core 3D printing features such as purge towers, heated build plates, and networking capabilities.

The specific patent at issue in this IPR is U.S. Patent 9,421,713, titled "Additive manufacturing method for printing three-dimensional parts with purge towers". This patent generally describes methods for improving extrusion-based additive manufacturing by using purge operation techniques, which involve printing temporary "purge towers" to clear and prepare the print head during material changes (e.g., color swaps) in 3D printing. The case is being heard by the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office, a specialized administrative court for challenging patentability. The IPR petition was filed on December 17, 2024, and while it was instituted and pending, the PTAB has since issued a ruling on June 9, 2026, finding that patent US9421713B2 is valid, indicating a final written decision has been reached regarding the challenged claims.

This case is particularly notable within the 3D printing industry due to the clash between an established industry leader, Stratasys, and a rapidly growing, disruptive newcomer, Bambu Lab. Stratasys's assertion of patents covering fundamental 3D printing functionalities against Bambu Lab's popular consumer devices highlights a strategic effort to protect its intellectual property and market position. The IPR serves as a critical parallel challenge to the validity of one of Stratasys's asserted patents, influencing the outcome of the broader infringement litigation and potentially setting precedents for how intellectual property is enforced and challenged in the competitive and innovative 3D printing market.

The patent litigation involves parallel proceedings: a patent infringement lawsuit filed by Stratasys Inc. in the Eastern District of Texas, and an Inter Partes Review (IPR) initiated by SHENZHEN TUOZHU TECHNOLOGY CO., LTD. and other entities before the Patent Trial and Appeal Board (PTAB).

Key Legal Developments and Outcome

I. District Court Patent Infringement Litigation (Stratasys, Inc. v. Shenzhen Tuozhu Technology Co. Ltd. et al., E.D. Tex., Case No. 2:24-cv-00644)

• Filing & Initial Pleadings:

  • 2024-08-08: Stratasys, Inc. filed a patent infringement lawsuit against Shenzhen Tuozhu Technology Co., Ltd., Shanghai Lunkuo Technology Co., Ltd., Bambulab Limited, and Tuozhu Technology Limited, among others, in the U.S. District Court for the Eastern District of Texas. The complaint alleged infringement of multiple patents related to 3D printing technology, including U.S. Patent No. 9,421,713. Stratasys sought a declaration of infringement, damages (including enhanced damages for willful infringement), and a permanent injunction.
  • 2024-09-11: Waivers of Service were returned executed by Bambulab Ltd., Shanghai Lunkuo Technology Co. Ltd., Tuozhu Technology Limited, and Shenzhen Tuozhu Technology Co. Ltd., with their answers to the complaint due by December 9, 2024.
  • 2024-09-25: Stratasys, Inc. filed a Notice of Voluntary Dismissal.
  • 2024-09-30: An Order was issued dismissing the case as to defendants Beijing Tiertime Technology Co., Ltd. and Beijing Yinhua Laser Rapid Prototyping and Mould Technology Co. Ltd.

• Pre-trial Motions/Discovery Milestones (as of last retrieved docket data):

  • As of November 12, 2025, the district court docket indicated that fact and expert discovery were ongoing and not yet closed, and a Markman hearing was scheduled for December 3, 2025.
  • The district court case was initially consolidated with another case, No. 2:24-cv-00645.
  • The trial in the parallel district court proceeding was estimated to occur around July 2026, which would likely be after the statutory deadline for a final written decision in related IPR proceedings.

II. Parallel PTAB Inter Partes Review (SHENZHEN TUOZHU TECHNOLOGY CO., LTD. et al. v. Stratasys Inc., IPR2025-00321)

• Filing & Institution:

  • 2024-12-17: SHENZHEN TUOZHU TECHNOLOGY CO., LTD., along with other entities including BAMBULAB LIMITED, SHANGHAI LUNKUO TECHNOLOGY CO. LTD., TUOZHU TECHNOLOGY LIMITED, and BAMBULAB USA, INC., filed a Petition for Inter Partes Review challenging the validity of U.S. Patent 9,421,713.
  • The PTAB instituted the IPR, though the specific date of the institution decision was not directly found in the search results. The case status is listed as "Instituted and pending."

• Claim Construction:

  • Details of the PTAB's specific claim construction for IPR2025-00321 were not explicitly identified in the search results.

• Outcome:

  • 2026-06-09: The PTAB ruled that U.S. Patent 9,421,713B2 is valid. (This information is provided in the prompt's existing case summary. A direct link to the Final Written Decision for IPR2025-00321 confirming this specific outcome was not found in the search results.)

• Effect on Litigation:

  • The PTAB's ruling on June 9, 2026, finding the challenged patent claims valid in IPR2025-00321, would likely strengthen Stratasys's position in the parallel district court infringement lawsuit regarding U.S. Patent 9,421,713. Conversely, it would be a setback for SHENZHEN TUOZHU TECHNOLOGY CO., LTD. and the other petitioners in their efforts to invalidate the patent. While specific estoppel effects on the district court litigation would depend on the exact claims and grounds challenged and decided, a PTAB decision affirming validity typically carries significant weight.

The overall status is that the IPR is concluded with a finding of validity, and the related district court litigation, filed in August 2024, was ongoing as of late 2025, with a Markman hearing scheduled for December 2025 and an estimated trial in mid-2026. The impact of the PTAB's validity finding on the district court case would be a crucial next development.

The plaintiffs, SHENZHEN TUOZHU TECHNOLOGY CO., LTD., BAMBULAB LIMITED, SHANGHAI LUNKUO TECHNOLOGY CO. LTD., TUOZHU TECHNOLOGY LIMITED, and BAMBULAB USA, INC., are represented by a team of attorneys from Fish & Richardson P.C. in IPR2025-00321.

The counsel of record for the plaintiff(s) are:

• Patrick J. Bisenius (Lead Counsel)
  • Firm: Fish & Richardson P.C., Minneapolis, MN.
  • Note: Patrick Bisenius is registered with the USPTO (Reg. No. 63,893) and is listed as an attorney for the Petitioner in the IPR proceeding. His practice typically focuses on patent litigation before district courts and the PTAB.
• Michael T. Hawkins (Counsel)
  • Firm: Fish & Richardson P.C., Minneapolis, MN.
  • Note: Michael Hawkins is registered with the USPTO (Reg. No. 57,867) and is listed as an attorney for the Petitioner. His experience includes patent prosecution and litigation.
• Joshua A. Griswold (Counsel)
  • Firm: Fish & Richardson P.C., Minneapolis, MN.
  • Note: Joshua Griswold is registered with the USPTO (Reg. No. 46,310) and is listed as an attorney for the Petitioner. His practice areas often involve complex intellectual property disputes.
• Cameron A. Ubel (Counsel)
  • Firm: Fish & Richardson P.C., Minneapolis, MN.
  • Note: Cameron Ubel is registered with the USPTO (Reg. No. 77,081) and is listed as an attorney for the Petitioner. He is involved in patent litigation, particularly in the technology sector.

Stratasys Inc., the defendant and patent owner in IPR2025-00321, is represented by attorneys from McDermott Will & Emery LLP. The counsel of record includes several partners with extensive experience in patent litigation and post-grant proceedings. Additionally, Stratasys has in-house legal counsel.

Here is the breakdown of the identified counsel:

Outside Counsel:

• Brian W. Oaks

  • Role: Partner, likely lead counsel for PTAB proceedings.
  • Firm: McDermott Will & Emery LLP, Austin, TX.
  • Experience: Focuses on IP law with a particular emphasis on patent post-grant trials, patent litigation, and patent portfolio development. He has led over 200 post-grant trials at the PTAB, representing both petitioners and patent owners. He litigates patent disputes across various technologies, including internet, complex software, and telecommunications.

• Aashish G. Kapadia

  • Role: Partner.
  • Firm: McDermott Will & Emery LLP, Austin, TX.
  • Experience: Represents clients in patent litigation, post-grant trials, and patent prosecution. His background in electrical and computer engineering provides strategic insight into technologies such as computer hardware, software, and telecommunications. He regularly represents clients in inter partes review proceedings at the USPTO.

• Kevin J. Meek

  • Role: Partner, Managing Partner of McDermott's Austin office.
  • Firm: McDermott Will & Emery LLP, Austin, TX.
  • Experience: Concentrates on patent litigation, prosecution, and licensing, with extensive experience in federal courts, the International Trade Commission, and post-grant proceedings before the USPTO. He has led dozens of trials involving advanced technologies, including consumer products, complex software, and semiconductor and telecommunications applications.

• Syed K. Fareed

  • Role: Partner.
  • Firm: McDermott Will & Emery LLP, Austin, TX.
  • Experience: Guides multinational clients through high-stakes IP disputes, often serving as lead counsel in high-tech patent litigation. He represents clients in district courts, the Federal Circuit, the ITC, and the USPTO, across sectors like computer software, e-commerce, telecommunications, and semiconductors.

In-House Counsel:

• Vered Ben Jacob
  • Role: Chief Legal Officer.
  • Firm: Stratasys Inc.
  • Experience: Responsible for all legal and IP matters for Stratasys, leading the global legal and compliance function, and overseeing the company's global Intellectual Property function since 2018.