Kim introduces multi-material micro-LEGO
New developments in the field of micromanufacturing are detailed in Assistant Professor Seok Kim’s new paper, “Microassembly of Heterogeneous Materials Using Transfer Printing and Thermal Processing,” published this week by Scientific Reports.
Kim’s work introduces a new level of microassembly (termed ‘micro-LEGO’) that involves multiple materials. Previous techniques of micro-masonry—a field in which Kim is a leading scientist—only allowed a single material to be assembled at a time, building upon each other with reversible dry adhesives.
This approach was expanded into micro-LEGO and now researchers can assemble not only silicon (semiconductor), but also silicon dioxide (dielectric), gold (metal) and SU8 (polymer).
“This was challenging because we had to deal with different materials, which means we have to understand different material properties in the context of developing different transfer printing and thermal joining processes,” said Kim.
These various materials serve different functions and purposes, and set the foundation for future applications of micro-LEGO. The ability to assemble four different heterogeneous materials will aid in the development of micro devices, including but not limited to optical resonators or RF MEMS (radio frequency microelectromechanical system) switches.
“Previous micro-masonry is very limited when it comes to building actual devices because it deals with only one single material,” said Kim. “Now we’re dealing with four different materials so we can fabricate actual micro devices just by assembling different material constituents.”
He plans to continue his research in this area with his PhD student (Hohyun Keum, first author of the paper) by diversifying the materials even more and expanding the possible applications.
“This new technique enables building not just devices but also integrating existing devices together to create multifunction from just the one module,” Kim said. “That assembly can be done by this micro-level technique too—another future direction of my work.”
This work was done in collaboration with MechSE Assistant Professor Gaurav Bahl.