--- title: "Heteromerge MergeOne printhead enables multimaterial 2PP 3D printing" url: https://www.voxelmatters.com/heteromerge-mergeone-printhead-enables-multimaterial-2pp-3d-printing/ date: 2025-09-18 modified: 2025-09-18 lang: en author: "Davide Sher" description: "Multimaterial 3D printing, whether in metal or plastic, is a hot topic, and now it's getting to one of the most advanced areas of 3D printing: the micro- and nano-scale...." categories: - "3D Printing Processes" - "Micro 3D printing" - "Multi-material 3D printing" tags: - "future" image: https://www.voxelmatters.com/wp-content/uploads/2025/09/Frauenkirche_HR_Detail-e1758185445795-640x437.webp word_count: 836 --- # Heteromerge MergeOne printhead enables multimaterial 2PP 3D printing Multimaterial 3D printing, [whether in metal](https://www.voxelmatters.com/eth-students-develop-novel-rotational-multi-metal-3d-printing-process/) or plastic, is a hot topic, and now it's getting to one of the most advanced areas of 3D printing: the micro- and nano-scale. [German startup Heteromerge](https://www.voxelmatters.directory/company/heteromerge/) developed MergeOne, a printhead for multimaterial 2PP (Two-Photon Polymerization) 3D printing. With this innovative printhead system, Heteromerge makes it possible to fabricate high-precision, freeform 3D microstructures using multiple materials in a single print process. The Heteromerge printhead gives users the ability to design and print the smallest freeform structures with embedded functionalities. By combining different materials, users can tailor the structural, mechanical, and optical properties of their designs, enabling applications that were once impossible to achieve with mono-material printing. ## The very small matter of multimaterial printing The integration of multiple materials into a single structure allows for a much wider spectrum of functionality. Different materials enable the fine-tuning of properties such as stiffness, flexibility, or optical dispersion, directly within one component. This makes it possible to integrate multiple functions into compact 3D structures. The importance of this advancement is evident in fields like micro-optics, micro-mechanics, and micro-fluidics. For instance, one can fabricate compact compound optics that allow for miniaturized and lightweight camera modules used in mobile devices, drones, and minimally invasive medical instruments. Just as color printing overtook black-and-white printing in the 2D world, multimaterial printing is expected to replace single-material printing in 3D manufacturing. Users will design their desired structure, choose the materials, and achieve the final result in a single seamless process. To realize this vision, a new technological approach is required. Heteromerge has taken the first steps with the MergeOne printing platform, which is built on the principle of material exchange in an open-fluidic system. ## Retrofitting 2PP systems for open-fluidic Any existing 2PP 3D printer could be upgraded to print at the nanoscale with multiple materials. The Heteromerge MergeOne system integrates seamlessly with existing 2PP printers, extending their functionality to multimaterial production without compromising alignment, speed, or resolution. The printhead ensures that when materials are changed, the object remains in the laser focus. This means users can achieve perfect alignment across different material sections, with overlay accuracy better than 50 nanometers. ![](https://www.voxelmatters.com/wp-content/uploads/2025/09/multi-materiaux.png.webp) Automated in situ material exchange eliminates manual handling, making multimaterial printing up to ten times faster than conventional methods. The full resolution of 2PP technology remains intact, allowing for lateral resolutions of down to 150 nanometers and vertical resolutions of down to 400 nanometers. The process is also substrate-independent, allowing printing on single devices, existing components, or large-scale wafers, whether transparent or opaque. One of the most important innovations in Heteromerge’s approach is its patented open-fluidic replacement system. This system allows for in situ material exchange during printing, ensuring continuous workflow without losing focus or alignment. Because of this, Heteromerge enables multimaterial prints with extraordinary precision while reducing printing times dramatically. The technology is flexible enough to support both small prototypes and large fabrication runs. Its volume-conserving material supply makes it ideal for large-area applications, while still being efficient for delicate, nanoscale devices. ![](https://www.voxelmatters.com/wp-content/uploads/2025/09/two-material-composite-microlens.jpeg.webp) ## Multi-material optics and beyond Heteromerge’s multimaterial 2PP printing has wide-ranging applications across several industries. In optics, for example, it enables the fabrication of multi-material compound lens systems. These lenses consist of individual elements with different refractive indices, allowing designers to optimize performance across a broad spectrum. Thanks to 2PP’s ability to produce freeform polymer optics with a surface finish below 10 nanometers RMS, the resulting lenses are not only highly precise but also lighter, cheaper to assemble, and more durable than traditionally manufactured optics. This freeform approach simplifies design, reduces assembly costs, minimizes weight, and decreases sensitivity to mechanical impacts. Multi-material technology further enhances performance by optimizing broadband lens properties, tightening focus, improving off-axis imaging, and increasing tolerance to misalignments. Such advancements are invaluable for applications like beam scanning, optical data processing, and imaging systems. In medicine, multimaterial printing enables the production of micro-needles and minimally invasive surgical tools. In microfluidics, it makes it possible to create highly functional lab-on-a-chip devices with integrated flow channels. In mechanics and data processing, it provides the foundation for compact, functional components at micro- and nano-scales. Heteromerge has already achieved several milestones on its path to transforming 3D micro-printing. The initial proof of concept demonstrated that multimaterial printing could be realized through material exchange in an open-fluidic system. From there, the idea of the multi-material printhead emerged and was validated with prototype development. The company secured funding from the German government as part of its support for high-tech spin-offs from scientific institutions. Prototypes of the multimaterial printhead were then delivered to pilot customers through a program supported by pre-seed investors. The successful launch of the MergeOne platform has now made multimaterial 2PP printing a reality for research and industry. Looking forward, Heteromerge is committed to further developing both its printhead technology and control software. The roadmap includes expanding the range of functional microstructures and enabling volume production. To accelerate this journey, the company is actively seeking seed funding and dedicated partners who can support its vision financially and professionally.