walls of the embedded microfluidic structure directly this means that the energy transfer mechanism is such that the embedding layer is transparent to it even if the embedding layer is not completely transparent it will be substantially transparent and a great deal of the energy directed to the exposed embedded microfluidic structure surface will be received by the surface in the example of a silicon structure the exposed embedded structure surface can be silicon and the embedding layer can be silicon oxide one example of such a heat transfer mechanism may be but is not limited to exposing the substrate to laser radiation within the visible spectrum laser is an acronym for light amplification by stimulated emission of radiation one result of this type of light generation is the light has a single frequency and phase this visible laser light will be able to penetrate the embedding layer to strike the exposed embedded microfluidic structure surface causing that surface to heat up in the example of a silicon microfluidic structure the laser can locally heat the exposed silicon surface up to or just below the melting temperature of silicon when this embedded exposed silicon structure surface is heated in a reactive environment the reactive gas in the atmosphere can form with the silicon structure that is heated to form a reaction product when the reactive atmosphere is oxygen a.