Work of the group focusses on:
- Two-photon-polymerisation, applications and systems
- Generation of microstructures using FEM
- Metrology applications using EUV and X-Ray radiation
Lithographic processes are currently being routinely used for the mass production of computer chips. However, miniaturisation is now being used in many other areas, due to microscopic and nanolithography processes. Among these are microstructured surfaces, innovative micro-optics, microfluidic components and micro-implants for medical uses.
By using femtosecond lasers, generative processes (micro-nano rapic prototyping) and removal processes are possible. The group NLT carries out research and development in this field of new technologies, components and systems for research and applications. Apart from this, metrology equipment for examining microstructures using EUV and X-ray radiation are being developed.
Two-Photon Polymerisation: Applications and Systems:
Two-photon polymerization (2PP) is a rapid prototyping process which can be used for generating components and surfaces with almost any micro- or nanostructure. Photopolymers are mainly used in this area. These included standard products from the field of chip lithography such as SU-8, or special femto-bond materials geared to use on our systems. The photopolymer is irradiated by a femtosecond laser, and cured. Thus, it is possible to make almost any micro- or nano-geometry. 2PP is already in use in the following fields:
- Bio-medical uses
- Surface structuring
- Photonic crystals
- And many more applications…
A volume of up to 10 cam x 15 cm x 10 cm can be processed, continually (non-stepped, non-stitched) at a high speed.
The Laser Zentrum Hannover e.V. can offer the complete process chain: materials, customer optimized equipment, installation and training.
Generation of microstructures using femtosecond laser ablation
Femtosecond lasers can be used for ablation of many materials in the micrometer range. The material spectrum is uncommonly large, and metallic materials, non-metal materials, transparent, flammable and even gel-like materials can be processed. This can be done with almost no thermal stress or melting of the material.
For example, these processes are currently being researched in the field of ophthalmology, for developing implants to avoid cataracts. This disease occurs when the eye can no longer control the inner pressure of the eye. Intelligent, pressure regulating micro-implants can be made out of micro-tubes using a femtosecond laser.
Metrology applications using EUV- and X-Ray Radiation
The group carries out research and development of innovative laboratory beam sources, metrology technology and lithographic techniques for research and applications in the hard ultraviolet spectral area (EUV) and x-ray range:
- EUV- and X-ray metrology
- Material investigations
- Design and construction of metrology equipment
Industry needs complete measurement systems that can be used on site, especially for special optics. Based on extensive experience with EUV reflectometers for Wolter-Shell type I collectors, concepts for characterizing multilayer coated collectors (LPP) have already been successfully tested.
A further main area of work is in miniaturizing metrology equipment and lithographic apparatus, with the goal of making them available for daily research applications in university or industrial research labs. Presently, this equipment is only used by large research labs (i.e. synchrotrons), due to size and costs.
Current scientific work and projects:
- 2PP-Lightwave „Parallelization of two-photon-polymerization to increase the effective writing speed “ (EU)
- Phocam „Development of an industrial platform for two-photon-polymerization“ (EU)
- Generation of micro- and nanostuctured implants for medicine:
- Transregio SFB 37 subproject C3 „Microstents for use to reduce increased intraocular pressure (DFG)
- REMEDIS subproject B2 „Diffractive-refractive micro-structured implants as a substitute for clouded lenses” BMBF)
- Micro-perforated implants for otolaryngology applications
- Arrangement of nanoparticles using laser-induced transferal (DFG)