Miltenyi Biotec patents the “light sheet” to overcome the limits of volumetric 3D printing
Miltenyi Biotec has filed an international patent proposing a new approach to volumetric 3D printing. The system uses a thin inclined “light sheet” combined with a second structured beam to control resin polymerization. The goal is to solve one of the main problems of current volumetric technologies: achieving high resolution and larger print volumes simultaneously.
The patent WO2025088201A1, entitled “Methods to Improve 3D Printing Using Two-Color Polymerization”, describes a variant of two-color photopolymerization. A first beam temporarily prepares the photoinitiator. A second beam activates the reaction only where the two light fields coincide.
- Miltenyi Biotec proposes a movable “light sheet” instead of the traditional focal point
- The technology uses two wavelengths to control volumetric polymerization
- Goal: overcome the trade-off between resolution and part size
- Possible applications in biomedical microfabrication
From the focal point to the light sheet
The main difference compared to existing volumetric technologies concerns the geometry of the optical field used to control polymerization.
The technology falls into the same conceptual family as the xolography developed by xolo GmbH, where two wavelengths control polymerization in a volume of resin without proceeding layer by layer. The main difference introduced by Miltenyi concerns the shape and movement of the optical fields.
Instead of working only with a volume illuminated through a focal point, the patent proposes transforming one of the beams into a thin, elongated surface. This sort of movable light plane can be moved through a larger area of the material.
From layer-by-layer printing to volumetric printing
Commercial resin printers build objects layer by layer. Volumetric printing seeks to completely eliminate the concept of layers.
Most commercial resin printers, including SLA, DLP, and MSLA, follow a repetitive cycle: exposure, layer solidification, separation, platform movement, new layer. Volumetric printing works differently.
The object is defined through the spatial distribution of light within the resin. It can form simultaneously at multiple points in the volume.
Absence of layer lines, potentially more uniform properties, speed independent of part height, possibility of creating internal structures without traditional supports.
The scalability problem
Volumetric systems work well on small volumes, but increasing the size creates significant technical challenges.
The historical problem of volumetric technologies is scalability. When the volume is small and light can be controlled with great precision, everything works well. However, as the size of the part increases, several aspects become more difficult to manage.
Optical control becomes more complex. Energy uniformity decreases. Resin management requires more sophisticated solutions. Heat dissipation and polymerization precision also represent growing challenges.
Two-color photopolymerization
The chemical principle underlying the technology involves two different wavelengths working together to activate polymerization only at the desired point.
Two-color photopolymerization, also called “two-color polymerization”, is the fundamental chemical principle of the technology. The system requires photosensitive materials specifically designed to respond to two different wavelengths in a coordinated manner.
The first beam prepares the photoinitiator by bringing it to an intermediate state. The second beam completes activation only where the two fields overlap. This selective spatial control allows precise definition of where solidification occurs.
Application prospects
The patent does not specify immediate commercial applications, but biomedical microfabrication represents a possible initial market.
Miltenyi Biotec operates mainly in the biotechnology and biomedical research technology sectors. Biomedical microfabrication could represent the first field of application of the technology.
The ability to create complex three-dimensional structures without supports and with uniform properties could be particularly useful for tissue scaffolds and microfluidic devices. It remains to be seen when and if the technology will move from the patent phase to commercialization.
Miltenyi patents volumetric light-sheet 3D printing to increase part sizes – 3D Printing
article written with the help of artificial intelligence systems
Q&A
What is the main objective of Miltenyi Biotec's patent?
The goal is to resolve the trade-off between high resolution and large print volumes in current volumetric technologies. The system aims to achieve both characteristics simultaneously using a novel optical approach.
How does the two-color technology described in the patent work?
The system uses a first beam to temporarily prepare the photoinitiator and a second beam to activate the polymerization reaction. Solidification occurs only at specific points where the two light fields coincide.
How does the 'light sheet' differ from existing volumetric methods?
Unlike technologies that use a focal point, this patent transforms one of the beams into a moving, thin, elongated surface. This allows control of polymerization over a larger area of the material compared to traditional systems.
What is the fundamental difference between volumetric printing and layer-by-layer printing?
While traditional printers like SLA build objects layer by layer through repetitive cycles of exposure and movement, volumetric printing defines the object via the spatial distribution of light. This enables simultaneous formation of the object at multiple points within the volume without layers.
To which conceptual family does this new technology belong?
The technology belongs to the same family as xolography, where two wavelengths control polymerization directly within the resin volume. The novelty introduced by Miltenyi specifically concerns the geometry and movement of the optical fields used.
