The novel IP-n162 photoresin expands the opportunities in creating innovative miniaturized optical systems by means of 3D Microfabrication
Karlsruhe. Nanoscribe introduces the new IP-n162 photoresin, a printing material with special properties for microoptical elements such as microlenses, prisms or complex freeform optics. The photoresin features a high refractive index in combination with a high dispersion, which corresponds to a low Abbe number. These properties are particularly beneficial for the 3D Microfabrication of innovative microoptical designs, even without rotational symmetries, and for compound refractive optical systems with three-dimensional shapes and more than one refractive surface. With a low absorption in the infrared region, the photoresin is the best choice for the fabrication of infrared microoptics, but also for applications where low absorption losses are critical such as optical communication, quantum technology and photonic packaging.
To meet the needs of advanced optical designs, Nanoscribe introduces a new printing material for 3D Microfabrication: IP-n162. The novel printing material is specifically designed for additive manufacturing based on Two-Photon Polymerization (2PP) in a straightforward 3D printing workflow. The high refractive index material enables innovative microoptical designs with high shape accuracy and takes high-precision microlenses and freeform 3D microoptics to the next level.
Thanks to their optical properties, high refractive index polymers facilitate a variety of applications related to disruptive technologies. For example, in optoelectronic applications they enhance the visual properties of display devices or camera and projector lenses. Moreover, the availability of these materials for 3D Microfabrication can establish a new class of complex 3D microoptical elements in much smaller sizes than possible with today’s classical technologies. Examples are microlenses in miniaturized imaging systems, endomicroscopy and 3D sensing for AR/VR applications.
High refractive index and high dispersion
The main advantage of IP-n162 is its high refractive index of 1.62 at a wavelength of 589 nm. Compared to Nanoscribe’s other 2PP resins, the new printing material offers the highest refractive index. In addition, the printing material exhibits a low Abbe number of 25, making it the Nanoscribe resin with the highest dispersion. The optical properties of structures printed with IP-n162 are close to optical polymers typically used in injection molding and can be compared to polycarbonate or polyesters. IP-n162 can be easily used for 3D printing on the microscale, enabling almost any thinkable microoptical design. Thus, the direct prototyping of 3D or 2.5D microoptics is achieved in an easy and quick process. And for subsequent replication processes, the time-consuming and expensive iterative fabrication of injection molds by diamond milling within the development phase is no longer necessary.
One possible application of high dispersion materials is the fabrication of achromatic optical systems. By printing compound optics, consisting of elements made of a lower refractive index next to a higher refractive index material such as IP-n162, achromatic optical systems can be additively manufactured on the microscale. “The currently commercially available resins are too similar in their refractive indices, which limits innovations in microoptical systems. IP-n162 has promising optical properties to develop a useful achromatic system required, for example for display devices, ultra-sensitive detectors and medical applications,” comments Matthias Kraus, scientific researcher at the University of Applied Sciences in Jena, who has pilot-tested IP-n162 in novel optical applications.
3D Microfabrication drives a new era of freeform microoptics
“A high refractive index photoresin like IP-n162 gives the designer additional freedom to create lenses that are more powerful, thinner, less curved, more compact and that can be also 3D-printed faster and cheaper” states Simon Thiele, project participant of the BMBF funded project PRINTOPTICS and CTO of the spin-off company of the same name. In this project, Nanoscribe is partnering with the University of Stuttgart and the medical technology company Karl Storz in the printing of miniature optics on fibers for endoscopy applications. “The most powerful design I realized with IP-n162 was a complex optical system consisting of two lenses with complete freeform surfaces to achieve a distortion-free image. A special feature is the integrated diffractive lens containing fine stair-structures on the top of the lens to correct the color error,” says Thiele about his experiences with the new photoresin. “The high refractive index of IP-n162 helps to make these steps smaller and to reduce stray light”, Thiele summarizes the advantages of IP-n162.
The medium-sized company develops and produces 3D printers and maskless lithography systems for microfabrication as well as specially developed printing materials and application-specific solution sets. The specialist for additive manufacturing of high-precision structures and objects on the nano, micro and mesoscale was founded in 2007 as a spin-off of the Karlsruhe Institute of Technology (KIT). With the Carl Zeiss AG (ZEISS), Nanoscribe has a strong partner and investor at its side. Today, with more than 70 employees and subsidiaries in China and the USA, Nanoscribe has become the market and technology leader. More than 2,000 users and operators at top universities and innovative industrial companies worldwide benefit from the groundbreaking technology and application tailored solutions for 3D Microfabrication.