There has been a new twist in the Stratasys vs Bambu Lab lawsuit. Bambu Lab, a leading manufacturer of desktop FFF 3D printers, has challenged the validity of Stratasys’ patents before the US Patent and Trademark Office’s (USPTO) Patent Trial and Appeal Board (PTAB), opening a new front in the ongoing legal battle.
Shenzhen Tuozhu, Bambu Lab’s owner and primary defendant in the Stratasys lawsuit, filed four separate challenges at the PTAB against key Stratasys patents cited in the original lawsuit.
One patent (9,592,660 B2) covers a heated build platform designed to improve print quality. Another (9,421,713 B2) concerns “purge towers,” structures printed alongside objects to clear material when switching between print heads. A third (8,562,324 B2) protects methods for connecting and controlling networked 3D printers.
In these three cases, the PTAB accepted Bambu’s request for an Inter Partes Review, concluding there is a “reasonable likelihood” that Bambu can show the inventions were anticipated or rendered obvious by earlier work.
Not all of Stratasys’s portfolio is at risk. A fourth patent (8,747,097 B2), covering the remote management of 3D printers with networking and scanning capabilities, has been spared after the USPTO Director denied Bambu Lab’s request for a review.
As it stands, Bambu leads 3-1 in its PTAB challenge. The outcome of the remaining proceedings could have major implications for Stratasys’ patent-infringement lawsuit against Bambu Lab, which is progressing in the Eastern District of Texas, Marshall Division. It is important to keep in mind that institution is not a “loss” in itself; Stratasys still has full trial to defend, and outcomes historically vary.
Final PTAB rulings on the contested patents are expected by mid-2026, while trials are slated to commence in Texas next June. If the USPTO invalidates key patents, Stratasys’ infringement allegations would be blunted. However, if the patents are upheld, the industrial 3D printer OEM’s legal standing could be considerably strengthened.
Stratasys vs Bambu Lab: The legal battle so far
The legal battle between Stratasys and Bambu Lab began in August 2024, when Stratasys filed two lawsuits claiming that Bambu’s X1C, X1E, P1S, P1P, A1, and A1 Mini 3D printers infringe ten of its patents. Stratasys requested a jury trial and is seeking financial damages, along with an injunction to prevent Bambu from selling the allegedly infringing printers.
Last October, Stratasys dropped charges against two defendants originally named in the lawsuit. Court documents show that Beijing Tiertime Technology Co., Ltd. and Beijing Yinhua Laser Rapid Prototyping and Mould Technology Co., Ltd. were removed from the case. These companies represent Tiertime, China’s first 3D printer manufacturer. It remains unclear why the Beijing-based firm was initially named, as there appears to be no direct connection to Bambu.
Previously, Stratasys sued Afinia in 2013, Tiertime’s U.S. distributor and partner, for patent infringement. In response, Afinia sued uCRobotics, the Chinese distributor of MakerBot 3D printers, over similar claims. Stratasys acquired MakerBot in June 2013, which later merged with Ultimaker in 2022.
February 2025 witnessed another update to the case when Bambu filed a motion to dismiss the lawsuit. The company argued that Stratasys’ claims, focused on the sale, importation, and distribution of 3D printers in the United States, do not apply to the Shenzhen-based parent company.
The defendants argued that the main allegations target Bambu Lab USA, which was not named in the complaint filed in the Eastern District of Texas. Bambu claimed this omission invalidates the suit under Federal Rule of Civil Procedure 19.
The court denied the motion on May 29, 2025. Judge Gilstrap emphasized that Stratasys’s case can succeed or fail based solely on the actions of the current defendants, regardless of Bambu Lab USA’s involvement. He added that any potential impact on Bambu Lab USA’s business is too speculative to justify making it a required party.
In June, Bambu Lab and Stratasys agreed to consolidate the lawsuit’s lead and member cases (2:24-CV-00644-JRG and 2:24-CV-00645-JRG) into a single case under Case No. 2:25-CV-00465-JRG.
Stratasys filed the consolidation request in May 2025. According to court documents, Bambu Lab did not immediately oppose the motion, which Stratasys argued constituted a waiver of the defendants’ right to challenge it. The U.S. District Court for the Eastern District of Texas, acting “out of an abundance of caution,” ordered Bambu Lab to confirm in writing whether it agreed to the proposed consolidation. On June 12, Bambu Lab responded, formally agreeing to merge the cases.
Bambu Lab launches PTAB offensive
Shenzhen Tuozhu filed its four requests in December 2024, with the PTAB responding in June 2025.
In case IPR2025-00257, which concerns Stratasys’ patent on heated build platforms (9,592,660 B2), Tuozhu argued that the invention isn’t novel but rather a combination of existing printing surface designs. The company cited U.S. Patent No. 5,503,785 and U.S. Patent Application 2014/0197627, claiming these earlier inventions already disclosed the features Stratasys later patented.
Stratasys’s 9,421,713 B2 patent is the subject of case IPR2025-00321. In this filing, Shenzhen Tuozhu contends that the patent is invalid because earlier inventions and publications had already disclosed the same concepts. Among other examples, the company cites an article and a YouTube video from the open-source RepRap community, along with KISSlicer’s 2012 Quick-start Guide, as prior art.
Meanwhile, in case IPR2025-00311, Shenzhen Tuozhu is challenging Stratasys’ 8,562,324 B2 patent, which covers networked 3D printing with features such as remote access, monitoring, and live video feeds. In the legal document, it argues that systems for coordinating and transmitting 3D printer instructions would have been obvious given existing technology.
For these three filings, the PTAB granted the petitioner’s request for review. This means the Board has agreed there is a reasonable likelihood that at least one of the challenged patent claims is invalid, and it will now conduct a full trial-like proceeding to evaluate the patents.
However, the patents have not been invalidated yet. Stratasys still has the opportunity to defend them through briefs, expert testimony, and oral hearings. Over the next 12 months, the PTAB will review the evidence and issue a final written decision on whether the claims will stand or be canceled.
Meanwhile, in case IPR2025-00354, Shenzhen Tuozhu’s request to challenge Stratasys’ patent 8,747,097 B2 was denied. Coke Morgan Stewart, Acting Under Secretary of Commerce for Intellectual Property and Acting Director of the U.S. Patent and Trademark Office, rejected the request, citing efficiency concerns. The Director specifically noted that Bambu’s Sotera stipulation was insufficient because Bambu still relied on unpublished system prior art in court, which the stipulation didn’t cover. This subtlety matters, as it shows why Stratasys won that denial.
In the official court filing, Stewart noted that the PTAB is expected to issue its final decision around July 14, 2026, while the district court trial in the Stratasys v. Bambu Lab case is scheduled for June 1, 2026, but is unlikely to start before July. She concluded that holding the PTAB review and the district court trial simultaneously would create inefficiencies and impose unnecessary burdens on both parties.
3D printing patent disputes
Patent battles have become a common theme within the 3D printing industry this year. In May, Florida-based Slice Engineering reached an agreement with Creality to settle a patent non-infringement lawsuit filed by the Shenzhen-based 3D printer manufacturer.
Creality filed the original declaratory judgment lawsuit in July 2024. It alleged that Slice had wrongly accused it of infringing two hotend patents, U.S. Patent Nos. 10,875,244 and 11,660,810. These cover specific mechanical and thermal features in Slice’s Mosquito 3D printer hotend.
Court documents show that Slice filed a countersuit in December 2024, arguing that Creality “has infringed and continues to infringe” on both patents. It also claimed that Creality refused to negotiate and denied allegations of harassing Creality’s partners, distributors, and customers. However, the case was ultimately dropped following a mutual resolution.
In other news, 3D printer manufacturer Markforged was ordered to pay Continuous Composites $17.34 million in a 3D printer patent infringement lawsuit, which began in 2021. In April 2024, a federal jury in the US District Court for the District of Delaware found that several of Markforged’s 3D printers infringed on a patent covering the method and apparatus for continuous composite 3D printing. Markforged responded, stating that it “strongly disagrees with this verdict and intends to seek to overturn it through post-trial motions in the District Court.”
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Featured image shows the Bambu Lab X1E and Stratasys Fortus 450mc. Image via 3D Printing Industry.
