Researchers at the University of Minnesota print microfluidic channels used for medical testing

Researchers at the University of Minnesota printed microfluidic channels that can automate the production of medical sensors and other applications. The U.S. Army Combat Capabilities Development Command Soldier Center assisted in the development of this research. The research is published in Science Advances.
Microfluidics, which is the scientific domain to which this new research applies, is a multi-billion-dollar production process. Microfluidics typically requires a clean room and photolithography equipment. Photolithography uses custom-built plates to create on a liquid silicone surface using light.
The research opens the door to eventually printing sensors directly onto curved biological surfaces, which would allow medical practitioners the ability to custom print sensors. The science of microfluidics controls this study. The researchers discovered how to print channels able to control fluids’ flow on a curved surface at a micron-scale (one-millionth of a meter). This testing method may be applied in COVID-19 cases and similar respiratory illnesses. It can also be used in cancer cases, for pregnancy testing and drug screening and delivery. These kinds of applications can make medical testing and drug delivery more efficient. Tests can be customized to individual patients without the need for a cleanroom.
The researchers used a 3D printer to create the microfluid channels in a single step on a surface. The custom printer successfully printed a sample in an open lab setting. The channels created were created in a circular surface that was roughly 300 microns in diameter. Fluid could flow through these channels. The researchers could control, pump, and re-direct the liquid using valves.

Printing these microfluidic channels outside a clean environment means that technology can be used for automated medical printing. Soldiers—hence the Army’s involvement—may also benefit from the technology. Sensors and treatment options may be developed in the field. This Network has reported on similar innovations in Australian Army field tests to replace metal combat parts.
“This new effort opens up numerous future possibilities for microfluidic devices,” said Michael McAlpine, a University of Minnesota mechanical engineering professor and senior researcher on the study. “Being able to 3D print these devices without a cleanroom 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,” said McAlpine, who holds the Kuhrmeyer Family Chair Professorship in the Department of Mechanical Engineering.