Polimi, Italian Institute of Technology, Italy
High Precision micro fabrication of 3D Optofluidic Circuits by Direct Laser Writing
Advantage in micro-ﬂuidics has been significantly enhanced by the development of simple and low cost
fabrication technique. Currently, the most influential of these techniques relies on planar micro-fabrication techniques based on photolithography. Although these techniques have been well established and are suitable for surface micro-fabrication, multilayer and multistep processes including stacking and bonding substrates are requred to form true three-dimensional (3D) microstructures.
ln order to solve these problems, the proposed projet is focused on the use of an advanced and automatic
controlled laser micromachining working station for direct writing inside the materials (transparent or photo-
sensitive polymeric media) and/or surface modiﬁcation (ablation). Take advantage from ultrashort-pulse laser, it possible to realize internal rnodification of the transparent materials (nanocracks) or a high localized photo-polymerization of sensitive polymeric materials, in the focus of the laser beam. Furthermore, direct writing has
several advantages over the conventional micro-channel molding: (i) it has great ﬂexbility due to the fact that it is resistless and mask-less; (ii) it is very suitable for rapid prototyping.
We are able in design hight precision micro-fabrication of several "material embedded" 3D micro photonics
structure as micro optics, optofluidic circuits, waveguides, reconfigurable opto-chips and pattemed surfaces for
many photonics application. After the volume laser irradiation, the optofluidic circuit has been obtained by
chemical eltching depending on the used material. It is very useful to easy realize 3-D microstructures
inside the materials. In parlicular:
- micro-optics to focus or collimate the light inside the microchannel
- any microfluidic circuit vvith integrated connection holder for optical fiber o waveguide
- specilic embedded microchannel for optic and optoelastic manipulatio of micro and nano particles and drops in isotropic and anisotropic (liquid crystal) fluidic environment
- microfluidic channel with different ratio of the geometrical dimension in order the study i) the physics behind the microfluidic flowing of the liquid crystal and ii) the new 3D alignment approach of the liquid crystal inside the microchannel by naniripples or configurable 3D microelectrode.
WG1: Integrated Microfluidic Photonics
WG3: Materials (soft, bio and nano) and technologies for optofluidic devices