College of Engineering News • Iowa State University

Joining forces to find the flow in printing core-shell metals

Iowa State’s Center for Multiphase Flow Research and Education (CoMFRE) sets the stage for Iowa State researchers to integrate their skillsets and use multiphase flows to solve challenges across all disciplines. The examples of innovative projects are many, and the latest includes a collaborative effort to develop a novel printing process for core-shell metals, often used in semiconductors.

The project was sparked when Martin Thuo, associate professor of materials science and engineering, asked Thomas Ward, associate professor of aerospace engineering, about a jamming that occurs when a slurry material (metal and solvent) evaporates in Thuo’s work in engineering flexible electronics.

Ward and Thuo joined forces with Andrew Martin (’17 Ph.D. materials science and engineering), a postdoctoral associate at Lawrence Berkeley National Laboratory and a previous Ph.D. student in Thuo’s group, and began to develop a new self-filtration process to create an almost smooth surface in core-shell particles after the carrier solvent evaporates.

The particles begin in a solvent solution, and then the goal is to understand how to print this material onto any surface.

“The most interesting part, for me, is the fluid mechanics of how one actually deposits a combination of solvent-liquid and solid particles (slurry) onto a substrate and, through evaporation, form a smooth surface,” Ward said.

Ward says this project is just the beginning of a valuable collaboration.

“For me, the next direction is to better understand the particular role of solvent/liquid evaporation. It has actually come up in other projects, and it is here where there may be more science to exploit for engineering purposes,” said Ward.