Web Content Display
Electronic circuits 3D-printed of conductive paste made of nickel nanoparticles in galinstan
March 11, 2018
Source: ASM International
Researchers at Oregon State University’s College of Engineering, Corvallis, have developed a conductive paste capable of 3D printing electronic circuits by mixing nickel nanoparticles into a galinstan alloy that is liquid at room temperature. The nickel nanoparticles thicken galinstan into a paste with a consistency suitable for additive manufacturing. Galinstan is a gallium-indium-tin alloy with the following approximate range of chemistries: 62-90Ga, 5-20In, 0-16Sn.
“The runny alloy [galinstan] by itself is impossible to layer into tall structures,” says Yiğit Mengüç, assistant professor of mechanical engineering and co-corresponding author on the study published in Advanced Materials Technologies. However, with the paste-like texture resulting from the addition of the nickel nanoparticles, it can be layered while maintaining its capacity to flow. “We demonstrated the potential of our discovery by 3D printing a very stretchy two-layered circuit whose layers weave in and out of each other without touching.”
Gallium alloys are already being used as the conductive material in flexible electronics; the alloys have low toxicity and good conductivity, plus they are inexpensive and self-healing. However, prior to the modification developed at OSU, printability was restricted to two dimensions. For this study, researchers printed structures up to 10 millimeters high and 20 millimeters wide, using sonication to mix the nickel particles and oxidized gallium into the liquid metal.
“The electrical properties of the paste are comparable to pure liquid metal, and the paste retains self-healing characteristics,” says study author Uranbileg Daalkhaijav, a Ph.D. candidate in chemical engineering at OSU.
Future work will explore the exact structure of the paste, how the nickel particles are stabilized, and how the structure changes as the paste ages. The Office of Naval Research Young Investigator Program supported this research.
Industries and Applications | Electronics
Industries and Applications | Nanotechnology
Materials Processing and Treatment | Additive Manufacturing
Materials Processing and Treatment | Powder Metallurgy
Metals and Alloys | Superalloys, Nickel, and Cobalt