The invention relates to a method for producing a bioreactor or a lab-on-a-chip system and bioreactors or lab-on-a-chip systems produced therewith. At least two different components are connected to one another here. It is an object of the present invention to specify a method with which bodies with very different melting points, specifically a ceramic and a polymer, can be connected to one another, independently of whether or not the surfaces to be connected are accessible from the outside. In the method according to the invention, a first body, made of polymer which is at least partially transparent to electromagnetic radiation of at least one wavelength ?, and a second body, made of a ceramic which absorbs electromagnetic radiation of the at least one wavelength ?, are interconnected. The first body can at least partially melt. In a first step, the first body and the second body are arranged in a contacting manner, forming contact faces in the process, such that the body can be melted in at least one area of its contact face to the other body. In a second step, the at least one meltable area of the contact face is caused to melt by irradiating electromagnetic radiation of the wavelength ? through the first body onto the meltable area of the contact face.