Abstract: The invention relates to a reversible microfluidic chip comprising at least one lower part and at least one upper part configured to come into contact with said lower part and to close said chip, said lower part and/or said upper part comprising a microfluidic structure, and said upper part comprising at least one layer of a flexible epoxide polymer material and at least one layer of a rigid epoxide polymer material, at least one part of the flexible layer being directly in physical contact with the lower part of the chip when said chip is in the closed configuration, to the method for the fabrication thereof, to the use of said upper part in a reversible microfluidic chip, to said upper part for producing said chip, and to the uses of said chip in various applications.