Laser-induced forward Transfer: a Direct-writing Technique for Biosensors Preparation

The focusing power of lasers make them adequate tools for patterning applications that require high levels of spatial resolution. Laser-induced forward transfer (LIFT) is a direct-writing technique allowing the deposition of tiny amounts of material from a donor thin film through the action of a pulsed laser beam. Although LIFT was originally developed to operate with solid films, it has been demonstrated that deposition is also viable from liquid films. In this case the transferred material is not vaporized; rather, a small amount of liquid is directly ejected from the film to the receptor substrate, where it deposits in the form of a microdroplet. This makes LIFT adequate for biosensors preparation, since biological solutions can be transferred onto solid substrates to produce micrometric patterns of biomolecules. In this case, the liquid solvent acts as transport vector of the biomolecules. The viability of the technique has been demonstrated through the preparation of functional biosensors showing similar performances and higher scales of integration than those prepared through more conventional techniques.