Abstract: A process for forming an integrated multiplex electrospray includes forming multiple holes in a ring extractor substrate to create a ring extractor. A nozzle array having multiple nozzles each nozzle defining a central axis is provided. A spacer layer is bonded to either the ring extractor or the nozzle array to form a bonded stack. The bonded stack is then aligned with remaining layer to align each of the multiple nozzles with one of the plurality of holes to less than 10 microns from concentric and the spacer layer then bonded intermediate between the ring extractor and the nozzle array layer. The spacer layer is then etched to provide fluid communication between multiple nozzles and the multiple holes of the ring extractor and form the spacer.