Hydroprinting Conductive Patterns onto 3D Structures

A novel and facile method for printing functional conductive patterns on 3D objects with unconventional angles using hydroprinting of silver nanoparticles (NPs) ink is developed. Silver NPs ink is inkjet printed on water soluble polyvinyl alcohol films. Sintering at room temperature is achieved by exposing the printed pattern to hydrochloric acid fumes. Electric circuits are hydroprinted at low temperature (50 °C) on various 3D‐printed structures and materials. The conductive patterns are hydroprinted on hard 90° angle objects and are assembled without any presence of sacrificial layer, which allows layer‐by‐layer overlap hydroprinting. In addition, electric Light Emmiting Diode (LED) circuits and heater are successfully hydroprinted. To show the applicability of the process we hydroprinted a fully functional Near Field Communication (NFC) antenna onto a curved object, which was successfully paired with a smartphone. Analysis of hydroprinted patterns shows that the resistivity is 17.1 times higher than silver bulk which is considered suitable in most application.