Micro & nanostructures

Generation and replication of micro and nanostructures

Our team has an expertise since many years on the following techniques used to create or replicate nano and micro-structures:

• Excimer laser micromachining: direct ablation of various materials (polymers, glass, IR materials …)
• Photolithography (mask aligner, Direct Writing Laser -DWL, soft-UV lithography): recording of micro-structures in photosensitive resin.
• Two-photon polymerization: generation of 3D micro-structures.
• Replication techniques (hot embossing and soft-UV embossing) in polymer materials. Nickel electrolysis is generally used to make the stamp for hot embossing.

We made the micro-structured parts of optical and/or microfluidic chips using these techniques for several research and industrial projects (MICROBIOMED, LEGOMEDIC, MIAMI …), [34-35, 43] and space applications, [30].

 LEFT : 25 µm height micro-pillars made by laser ablation (microfluidic application).  RIGHT : Metal on quartz mask made by Direct Laser Writing (laser welding application)

Researches in large edge-lit light guide unit (ELBU) optimization

Among the various LED lighting techniques, approaches involving the edge-lit light guide unit (ELBU) appear to be particularly well suitable for large-size format LED lighting applications, such as roadway and indoor lighting, LCD backlighting and photo-bioreactor lighting.

We have proposed and developed an original method of dot pattern generation dedicated to large-size format LGP design optimization, [42]. The proposed method is dedicated to design optimization of very large-size format edge-lit light guide units. It allows us to bypass limitations imposed on the maximum number of optical objects supported by most popular ray-tracing software packages.

The inherent advantage of the proposed method is its simplicity, combined with the fact that it can be implemented using programming tools of most popular ray-tracing software packages, such as ASAP.

The application of the proposed method is not restricted to large-size format rectangular LGP; it can also be adapted in principle, to design optimization of LGPs involving plastic slabs of arbitrary shape.