UpNano announces modified form of two-photon polymerization for high-resolution additive manufacturing.
UpNano GmbH has co-developed a novel manufacturing process for 3D-printed fused quartz objects in the millimeter and centimeter range. The process is based on a recent innovation from Glassomer GmbH, modified for two-photon polymerization (2PP) 3D-printing using UpNano’s NanoOne high-resolution printing system.
Manufacturing minuscule and complex 3D objects in glass is a challenging process, especially when working with high-quality fused silica (SiO₂) glass, which has an exceptionally high melting point. The only possible methods that can be used are based on non-commercially available equipment and include melting glass fibers using laser beams or fused deposition modeling to produce soda lime glass. Unfortunately, these methods often result in final products with rough surfaces that are undesirable.
UpNano and Glassomer have developed a rapid 3D printing process to produce smooth fused silica parts with features in the micrometer range.
3D printing fused silica parts in 3 steps
“It’s a three-step process”, explained Markus Lunzer, team lead of Materials & Application at UpNano in a press release. “The first step is to design and print the desired structure using all the advantages 2PP 3D-printing offers. The second step is to remove organic binder material followed by a high temperature sintering process, the third step.”
At the core of this is a newly developed nanocomposite called UpQuartz. In addition to SiO2 nanoparticles, it contains a specially designed polymer matrix that allows the composite to be 2PP 3D-printed. The printing process produces a “green part” that already has the shape of the final and desired structure. To obtain the fused silica product in the end, the polymer matrix must be removed. Heating the green part to 600°C effectively removes the polymer matrix, leaving behind the “brown part”. This is all SiO2 nanoparticles in the shape of the final product.
The structure is sintered and fused after exposure to 1,300°C. During the post-processing, the object undergoes isotropic shrinkage of approximately 30%. According to UpNano, this can easily be compensated for by an appropriate upscale of the green part using the company’s software.
“This innovative production process we developed is ideally suited for larger 3D-printed glass parts that require high-resolution and high-precision in the fields of engineering, chemical, medical or research applications, said Lunzer.”
Fused silica benefits and future applications
Fused silica offers superior optical properties, along with biocompatibility as well as high chemical inertness and heat resistance, making it suitable for a range of applications. UpNano claims this new development marks a significant advancement in the potential of 2PP 3D printing. In addition, the company’s printers have also recently been used to produce holistic embedded microfluidic chips as well as tungsten and platinum microstructures with sub-micrometer resolution.
“The speed, resolution, and versatility of our printers make them powerful tools for the mass production of highly precise parts,” said Bernhard Küenburg, UpNano’s CEO. “Our ever-expanding range of materials extends the range of applications. In due course, we will also expand the range of services we offer.”
