Nottingham University Shows UV-Based Process for Direct 3D Printing of Electronics
One of the main challenges in 3D printing electronic circuits is that the most effective material jetting processes for integrated multi-material electronic AM involve using photopolymers and silver nanoparticle (AgNP) inks, which require different types of 3D printing processes: photopolymers are cured by light while silver nanoparticles need to be sintered (that is they need heat). A recently published study by a team of researchers at the University of Nottingham’s Center for Additive Manufacturing describes a new method for sintering silver nanoparticles using the same UV-source which is used to cure the photopolymer.
A research domain known as multifunctional AM (MFAM) in its infancy looks to couple the positive attributes of AM with application in the electronics sector can have a significant impact on the development of new products; however, there are significant hurdles to overcome. This paper reports on the single step MFAM of 3D electronic circuitry within a polymeric structure using a combination of conductive and nonconductive materials within a single material jetting-based AM system.
The basis of this breakthrough is a study of the optical absorption regions of a silver nanoparticle conductive ink which leads to a novel method to rapidly process and sinter AgNP inks in ambient conditions using simple UV radiation contemporaneously with UV-curing of deposited polymeric structures.
Printing silver-nanoparticle inks alongside polymeric inks is challenging due to the high temperatures required for sintering, which can damage the polymer. Here, a method to sinter silver-nanoparticle inks using ultra-violet light which is absorbed by the nanoparticles generating localized heat is introduced. A polymeric ink is printed and solidified using the same UV source producing multi-material 3D structures in one process.
