Methods are provided for manufacturing flat devices to be used for forming a shape-retaining non-flat device by deformation of the flat device. Based on the layout of a non-flat device, a layout of a flat device is designed. A method for designing the layout of such a flat device is provided, wherein the method includes inserting mechanical interconnections between pairs of elements to define the position of the elements on a surface of the non-flat device, thus leaving zero or less degrees of freedom for the location of the components. Based on the layout of a flat device thus obtained, the flat device is manufactured and next transformed into the shape-retaining non-flat device by means of a thermoforming process, thereby accurately and reproducibly positioning the elements at a predetermined location on a surface of the non-flat device.