Continuous Liquid Interface Production

Continuous Liquid Interface Production
Name	Continuous Liquid Interface Production
Invented by	Joseph DeSimone
Year	2014
Company	Carbon (company)
Country	United States

Continuous Liquid Interface Production

Continuous Liquid Interface Production is a proprietary additive manufacturing method that enables rapid production of polymeric objects through photochemical curing. It integrates advances in photopolymerization, optics, and materials science to produce complex geometries with high throughput and resolution. The process has influenced manufacturing strategies across automotive, medical devices, consumer electronics, and aerospace sectors.

Overview

Continuous Liquid Interface Production operates as a continuous form of photopolymerization developed to overcome throughput limitations of layer-by-layer techniques such as Stereolithography and Fused deposition modeling. The method was commercialized by Carbon (company), co-founded by Joseph DeSimone, and demonstrated in pilot deployments with partners including Automotive Industry, Adidas, and Ford Motor Company. Early demonstrations attracted attention from institutions like Harvard University, Stanford University, and MIT for potential research collaborations and technology transfer. The technique has been discussed in media outlets and scientific venues including Nature (journal), Science (journal), and presentations at conferences such as SIGGRAPH and Automatica.

Technology and Process

The process uses an oxygen-permeable window to create a persistent "dead zone" above the window that prevents polymerization, enabling a continuous vertical build rather than discrete layers; this approach contrasts with Stereolithography and Digital Light Processing. A digital light projection system, often using micro-mirror arrays developed by companies like Texas Instruments, projects patterned ultraviolet light through the window to selectively cure resin, coordinated by motion control systems similar to those used by Fanuc and KUKA robotic platforms. The printer integrates software for slicing and exposure control akin to systems from Autodesk and Siemens PLM Software, and process parameters are optimized using data from rheometers and spectrophotometers from manufacturers such as TA Instruments and Agilent Technologies. Quality control and post-processing workflows draw on metrology practices established by Zeiss and Mitutoyo.

Materials and Chemistry

Resins formulated for Continuous Liquid Interface Production combine multifunctional acrylates or methacrylates with photoinitiators and inhibitors; suppliers and collaborators include chemical companies like BASF, Evonik, and Eastman Chemical Company. Photoinitiators commonly used are analogues to compounds evaluated in studies from laboratories at University of California, Berkeley and Caltech; oxygen inhibition layers are engineered using gas-permeable membranes similar to materials supplied by 3M and Saint-Gobain. Mechanical properties are tailored by copolymerization strategies described in patents assigned to Carbon (company) and research groups at University of North Carolina at Chapel Hill and University of Michigan. Biocompatible and high-temperature formulations have been developed for partners such as Stryker Corporation and GE Aviation.

Applications and Industries

Adoption has spanned industries: in Automotive Industry for rapid tooling and bespoke components with partners like Ford Motor Company and BMW, in Aerospace for lightweight brackets and flight hardware by suppliers to Boeing and Airbus, and in Medical Devices for patient-specific orthoses and surgical guides used by Mayo Clinic and Cleveland Clinic. Consumer goods collaborations include projects with Adidas and Specialized Bicycle Components for performance footwear and cycling components, while electronics manufacturers such as Samsung and Apple Inc. have explored prototyping applications. The method is used in research at institutions such as Lawrence Livermore National Laboratory and NASA facilities for advanced material studies.

Advantages and Limitations

Advantages cited include increased production speed compared with traditional Stereolithography and Selective Laser Sintering for polymers, finer surface finish compared with Fused deposition modeling, and enabling complex internal channels useful to GE Aviation-class heat exchangers. Limitations include dependency on proprietary resins and process recipes held by Carbon (company), constraints on material choices relative to thermoplastics used by companies like Stratasys, and challenges scaling to very large parts compared with gulf-scale manufacturing platforms used by General Electric. Regulatory and certification pathways for medical and aerospace parts require testing with standards from ASTM International and approvals from agencies such as the U.S. Food and Drug Administration and European Union Aviation Safety Agency.

History and Development

The method originated from research led by Joseph DeSimone and collaborators at University of North Carolina at Chapel Hill and was first published in high-profile journals mid-2010s; the technology was subsequently developed within Carbon (company) founded in 2013. Early industrial pilots were announced with partners including Adidas and Ford Motor Company between 2015 and 2017, followed by commercialization of systems and expanded materials portfolios through collaborations with chemical firms like BASF and Evonik. Funding and investment rounds included participation by venture firms and strategic investors such as Sequoia Capital, Google Ventures, and GV during the company's growth phase.

Intellectual Property and Commercialization

Commercialization has been driven by a portfolio of patents assigned to Carbon (company), covering aspects of photopolymerization, oxygen-permeable window design, and process control; enforcement and licensing activities have engaged corporate legal teams and led to cross-licensing discussions with entities like 3D Systems and Stratasys. Carbon pursued business models combining hardware sales, resin supply agreements, and cloud-based software services reminiscent of strategies from HP Inc. and Siemens PLM Software. The company's partnerships with industrial OEMs and medical device firms facilitated adoption while raising debates over open standards and competing approaches promoted at conferences such as Formnext and Rapid + TCT.

Category:3D printing