in the formation of multilevel liga microstructures , a preformed sheet of photoresist material , such as polymethylmethacrylate is patterned by exposure through a mask to radiation , such as x - rays , and developed using a developer to remove the exposed photoresist material . a first microstructure is then formed by electroplating metal into the areas from which the photoresist has been removed . additional levels of microstructure are added to the initial microstructure by covering the first microstructure with a conductive polymer , machining the conductive polymer layer to reveal the surface of the first microstructure , sealing the conductive polymer and surface of the first microstructure with a metal layer , and then forming the second level of structure on top of the first level structure . in such a manner , multiple layers of microstructure can be built up to allow complex cantilevered microstructures to be formed .