Advances in glass Microfabrication – Femtosecond laser irradiation followed by chemical etching
Femtosecond laser irradiation followed by chemical etching (F.L.I.C.E.) is an emerging technique for the fabrication of directly buried, three-dimensional microfluidic channels in silica.
The procedure attested in literature, which has been widely studied in the past years, consists of irradiating a glass slab and subsequently apply a chemical etching step. The results obtained by different research groups vary widely. In this paper we present a review of the most recent advancements of this technique discussing several critical factors that affect the aspect ratio, the length and the etching speed of the microchannel.
Microfluidic devices are interesting tools for synthetic chemistry and analysis: micro-reactors (μR) are proven to be extremely useful when dealing with unstable intermediates or with extremely fast exothermic reactions like oxidations or fluorinations with elemental fluorine (1-3). Micro total analysis systems (μ-TAS) offers the capabilities of preparation, transport, reaction, and analysis of very small volumes of biological samples. This is possible by squeezing onto a single substrate the functionalities of a biological laboratory (4, 5).
The microfeatures are embedded mainly onto three class of materials: metal, ceramics, glass / silicon or polymers. The choice of the material is basically due to the characteristics of the chemicals t