Engineers at the University of Maryland (UMD) have created a new multi-material 3D nanoprinting technique that was featured on the inside front cover of the July 21 issue of Lab on a Chip.
The team’s new technique – capable of printing tiny multi-material structures a fraction of the size of a human hair – offers researchers a faster, cheaper, and more accurate means to 3D print these highly complex structures because the process uses a very simple molding process that is widely used in most microfluidics labs.
To demonstrate their new approach, the researchers 3D nanoprinted a variety of multi-material components, including a five-material DNA structure, a multi-material “micro-cello,” and a four-material micro UMD logo.
“By providing researchers with an accessible way to 3D nanoprint multi-material systems that is not only much quicker, but also more precise than conventional methods, this work opens doors for emerging applications that demand microstructures with multiple materials, and in turn, multiple functions,” said Ryan Sochol, an assistant professor in mechanical engineering and bioengineering at UMD’s A. James Clark School of Engineering.
In one application of this new approach, Sochol’s Bioinspired Advanced Manufacturing (BAM) Laboratory is working with the Food and Drug Administration to apply this strategy to 3D nanoprint parts of the human eye that include complex anatomy with varying optical properties.
Andrew Lamont, lead author of the study and a Ph.D. student in bioengineering at UMD, presented early results of the team’s research at the International Micro Electro Mechanical Systems (MEMS) Conference in Seoul, Korea this past January, where the work was selected for the conference's Outstanding Paper Award.
In the past decade, scientists have struggled to 3D nanoprint structures with more than one material, as conventional techniques are limited in terms of time, cost, labor, and multi-material resolution. While 3D printing technologies have advanced greatly in recent years, printing at very small scales remains difficult.
“Unfortunately, prior challenges have resulted in only a handful of advancements based on multi-material 3D nanoprinting, with the vast majority including only two materials,” said Lamont, who developed the approach as part of his doctoral research. “But with our strategy, researchers can easily 3D nanoprint systems with high numbers of integrated materials at speeds and sizes not possible with conventional methods.”
The Clark School team has filed two U.S. provisional patents for their strategy, which is based on a process called “in-situ direct laser writing” and work published earlier this year. The multi-material structures are 3D nanoprinted directly inside of microchannels, with distinct liquid materials loaded into the channel one at a time for material-specific printing.
Once the printing process is finished, the microchannel enclosure can be removed, leaving behind fully integrated multi-material 3D structures in a fraction of the time, yet with better precision than the state of the art.
“This new ability to 3D nanoprint systems comprising materials with target chemical, biological, electrical, optical, and/or mechanical properties,” Sochol said, “offers a promising pathway to breakthroughs in areas including drug delivery, advanced optics, meta-materials, and microrobotics.”
A facile multi-material direct laser writing strategy
Andrew C. Lamont, Michael A. Restaino, Matthew J. Kim and Ryan D. Sochol
Lab Chip, 2019,19, 2340-2345
Ryan D. Sochol
Assistant Professor in Mechanical Engineering at UMD
University of Maryland (UMD)