The invention relates to a method for manufacturing a microfluidic chip, wherein said method comprises the steps of: providing a plate combined with a layer of inorganic silica gel of formula: (HsiO3/2)2n where n is an integer, and providing a lid; chemically activating the layer of silica gel and the lid, in order to make the layer of gel and the lid hydrophilic; mechanically combining the layer of gel and the lid to form a chip, such that the layer of gel forms an intermediate layer between the plate and the lid; annealing the chip, such that the layer of silica gel transforms into an intermediate layer made up of a SiO2 matrix for rigidly securing the plate to the lid. The invention also relates to a related chip and plate.