Microfluidic devices designed to help rapid diagnosis through blood
Researchers at Brigham Young University have demonstrated the ability to create microfluidic lab-on-a-chip devices with channels and valves smaller than ever before. Using a new 3D printing technique, the team has created chips with valves that are only 15 microns in size.
In a new paper published in Nature Communications, BYU engineering professor Greg Nordin and an interdisciplinary team of students and professors detail a generalized 3D printing process that enables the fabrication of much higher resolution 3D components without increasing the resolution of the 3D printer.
“We have taken the conventional 3D printing approach and generalized it to something that is broader in scope and has significantly more capability,” Nordin said. “This kind of expansion of the 3D printing paradigm to something beyond the traditional approach is what has enabled us to do all this miniaturization and integration.”
For the uninitiated, microfluidic devices are tiny, coin-sized microchips that include a set of nearly microscopic channels, valves and pumps etched into the material of the chip. They’re designed to sort out and analyze disease biomarkers, cells and other small structures from samples of liquids, like blood, through their channels.
Currently, the process to create these devices is time consuming and expensive. Due to the precision needed, new prototypes are typically created and tested in a cleanroom — a designated lab environment free from dust and other contaminants. Not only does the complicated and expensive nature of this process make it difficult to manufacture and distribute the lab-on-a-chip technology on a large scale, but it also puts major limitations on the size and type of microfluidic devices that can be made.
To overcome these obstacles, Nordin and his team turned to 3D printing methods back in 2017. In the latest publication, the group, including several undergraduates, innovated the way that printed layers on the chip are stacked. Instead of printing all the layers uniform, a technique typically seen in traditional methods of 3D printing, they changed the thickness, order, and number of layers stacked. These small changes resulted in dramatic advantages that now allow for the chip to be manufactured at a fraction of the cost, and at a much smaller scale than before.
“People have been working on lab-on-a-chip devices for 20+ years, but making prototypes in cleanrooms is an inhibitor to success,” Nordin said. “The road to market stops with clean rooms. With 3D printing, there is a road to market.”
This method of creating smaller microfluidic devices has important implications, but is work that not many others are taking on. According to Nordin, commercial 3D printers typically can’t produce the small sizes of channels and valves needed for microfluidic devices. Even the best commercial printers can’t print anything smaller than 27 microns, but Nordin’s new technology print as small as 7.6 microns.
“The bottom line is that commercial 3D printers and commercial materials just can’t meet the resolution needs we have for this type of technology,” Nordin said. “We’re printing chips with sophisticated components that have 60-70 tiny valves and 20-30 pumps — components that couldn’t be printed before now.”
Nordin and his team are hoping that their new development will set in motion more microfluidic research and development. Due to the lower cost it now takes to create these devices, this type of work will become more accessible to more people, and will result in more discoveries and progress in the field.
This development has already had a big impact on future BYU research as well. Nordin is currently facilitating research with six different BYU professors to better understand the real-world applications now possible with this new 3D printing method. Some of this multidisciplinary research is directed toward using this new printing technology to more accurately determine preterm birth biomarkers. Other aspects are focused on creating treatment plans for patients suffering with lung diseases and understanding tissue and cell activity on a smaller scale.
“Our new approach gets you over some of the big hurdles that block using this technology in real world applications,” he said. “We have yet to see that someone takes that and runs with it, but we certainly hope they will.”
