a method of making a sensor to measure an analyte in a solution is disclosed . the method comprises : providing a substrate , printing conductive ink on the substrate to form a plurality of electrode regions , depositing an electrical insulation to cover one of the electrode regions , sonically ablating the electrical insulation to form an array of pores through the electrical insulation to the conductive ink in the one electrode region , and depositing metal into the pores to form an array of electrodes in the one electrode region .