Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Microoptics – A smarter and faster way to replicate complex freeform structures


As a true 3D lithography technology Two-Photon Polymerization (2PP) allows to fabricate arbitrarily shaped microstructures especially suited for innovative optical applications. Up to now the technology has not reached industrial scale due to its rather limited throughput level. Fraunhofer ISC pursues different strategies to accelerate the process. The Institute presents its R&D competencies and latest technologies for optical and microoptical applications at the German Pavilion on the Photonics West in San Francisco from 31 January to 2 February 2017.

As of today, the fabrication of larger structures or larger batches of optical elements via 2PP takes too much time for an industrial scale production: 3D structures have to be processed point-by-point and only a single tiny focal volume of focused femtosecond laser pulses is used to solidify the material. To overcome this throughput bottleneck, the Fraunhofer ISC is currently investigating new approaches, methods and materials.

Illuminating a structure consisting of 10.000 microprisms reveals the logo of Fraunhofer ISC.

© K. Selsam-Geißler, Fraunhofer ISC

To accelerate the fabrication process Fraunhofer ISC applies nanoimprint techniques to replicate 2D or 2.5D structures for volume manufacturing. In this case, 2PP is used to create the “master“ structure from which a Silicone cast is molded. This mold is then used to replicate the master structure into either the same polymer as in the master structure or into other materials.

To test this approach, the Fraunhofer ISC has fabricated – among other tests – a complex array of 10.000 individual microprisms, with each a size of 60 µm. The fabrication of the entire prism pattern with a galvoscanner and dip-in lithography took several days. The copying of the master pattern took less than an hour.

To this effect, the Institute uses in-house synthesized inorganic-organic hybrid polymers of which the properties can be customized by chemical modification, formulation or even by the way of processing. In short, they can be particularly designed for 2PP applications and maintain their key properties (refractive index, low, absorption) even under harsh conditions. In addition, they offer superior optical properties, high stability and also biocompatibility.

Fraunhofer ISC develops hybrid polymers for various optical and microoptical applications according to customer requests. These materials can be adapted to particular processing methods and can be also molded with conventional techniques.

The smart combination of Two-Photon Polymerization with suitable methods of replication can provide both: true freeform 3D microstructures and a rapid and reliable fabrication technology for lot sizes larger than one. The technique also allows combining different forms like prisms, lenses, or pyramids in just one substrate. So, the fabrication of tailor-made geometries according to target specifications is possible. This paves the way to use 2PP for the industrial production of optical and microoptical elements.

In the future, Fraunhofer ISC will further optimize its materials and methods for the industry-relevant upscaling and replication of microoptical structures, in particular, of large area diffractive optical elements (DOE) that have yet remained a challenge.

Weitere Informationen:

Marie-Luise Righi | Fraunhofer-Institut für Silicatforschung ISC

More articles from Materials Sciences:

nachricht Breaking bad metals with neutrons
16.01.2018 | DOE/Argonne National Laboratory

nachricht White graphene makes ceramics multifunctional
16.01.2018 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>



Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

More VideoLinks >>>