3D printing breakthrough has potential in stretchable electronics

According to researchers at Oregon State University's College of Engineering, vertical structures are difficult to print with a liquid metal due to the low viscosity and high surface tension of the gallium alloy.

The team in the college's Collaborative Robotics and Intelligent Systems Institute put nickel nanoparticles into galinstan, a liquid metal alloy, to thicken it into a paste with a consistency suitable for additive manufacturing. According to the team, the resulting rheological modification of the liquid metal to a paste ‘drastically increases the fluidic elastic modulus and yield stress, rendering it 3D printable’. Their findings have been published in Advanced Materials Technologies.

"The runny alloy was impossible to layer into tall structures," said Yigit Mengüç, assistant professor of mechanical engineering and co-corresponding author on the study. "With the paste-like texture, it can be layered while maintaining its capacity to flow, and to stretch inside of rubber tubes. 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."