Method of forming a 3D conformal conductive pattern

A method of printing a conductive element comprising a conductive ink on a substrate having a three-dimensional surface, the method comprising:

• positioning the substrate;
• spraying, during an ink spraying step, the conductive ink through a nozzle by electrohydrodynamic (EHD) printing while applying an electric field to print a conformal conductive pattern on the three-dimensional surface of the substrate, wherein the conformal conductive pattern has a width to height aspect ratio in a range of 0.05:1 to 0.3:1;
• and
• curing, during a curing step, the sprayed conductive pattern to form a cured conductive pattern, wherein the conductive ink comprises:
• an electric field reaction element that is a water-soluble polymer including a heterogeneous element that can react to assist the movement of charges in the electric field;
• and
• a charge transfer element that provides a charge that moves in the electric field in the conductive ink,
• wherein the charge transfer element is split into ions in an aqueous solution state and moves as a charge, affecting the electric field reaction element to control the fluidity of the conductive ink,
• wherein the electric field reaction element and the charge transfer element are included in a weight ratio of 10:1 to 3:1,
• wherein the electric field reaction element and the charge transfer element interact with each other and determine ejection performance of the conductive ink in the electric field during the ink spraying step to conformally print the conductive pattern on the three-dimensional surface.