A team of researchers at the University of Minnesota and the U.S. Army Combat Capabilities Development Command Soldier Center have perfected a method of 3D printing microfluidic channels on a curved surface — a key step in the development of direct-printing bodily fluid sensors onto patients' skin.
"This new effort opens up numerous future possibilities for microfluidic devices," claims Michael McAlpine, University of Minnesota mechanical engineering professor and senior researcher on the study. "Being able to 3D print these devices without a clean-room means that diagnostic tools could be printed by a doctor right in their office or printed remotely by soldiers in the field."
"Being able to print on a curved surface also opens up many new possibilities and uses for the devices, including printing microfluidics directly on the skin for real-time sensing of bodily fluids and functions."
McAlpine's team developed a customized 3D printer that directly prints the microfluidic channels onto a curved surface at around 300 micron diameters — roughly three times the diameter of a human hair. Once printed, the channels were filled and fluid flow measured during control, pumping, and redirection via a series of valves.
While similar channels have been direct-printed before, the techniques have only been proven in a clean-room environment and on flat surfaces; in this study, by contrast, the channels were not only printed onto the curved surface but also in an open lab environment.
The team's work has been published in the journal Science Advances under open-access terms.