Scientists 3D print special fluid channels that could be used for...

In a groundbreaking new study, researchers from the University of Minnesota, in collaboration with the Soldier Center of the U.S. Army Combat Capabilities Development Command, 3D printed unique micrometer-sized fluid channels that could automate the production of diagnostics, sensors, and assays useful for a variety of medical Tests and other applications.

The team is the first to 3D print these structures on a curved surface. This is the first step in having one day printing them directly on the skin and capturing body fluids in real time.

The research is published in Advances in science, a peer-reviewed scientific journal published by the American Association for the Advancement of Science (AAAS).

Microfluidics is a rapidly growing field in which fluid flows are controlled in the micrometer range (one millionth of a meter).

Microfluidics are used in a variety of application areas including environmental sensing, medical diagnostics (such as COVID-19 and cancer), pregnancy testing, drug screening and delivery, and other biological tests.

The global market value for microfluidics is currently estimated at billions of dollars. Microfluidic devices are typically manufactured in a clean room with a controlled environment using a complex, multi-stage technique called photolithography. The manufacturing process involves a silicone fluid that flows over a textured surface and is then hardened so that the patterns form channels in the solidified silicone sheet.

In this new study, the microfluidic channels are created in a single step using 3D printing. The team used a purpose-built 3D printer to print the microfluidic channels directly onto a surface in an open laboratory setting.

The channels are about 300 microns in diameter – about three times the size of a human hair (one hundredth of an inch). The team showed that the flow of liquid through the channels can be controlled, pumped, and diverted using a series of valves.

Printing these microfluidic channels outside of a clean room environment could provide robot-based automation and portability in the manufacture of these devices.

For the first time, researchers were also able to print microfluidics directly onto a curved surface. In addition, they have incorporated them into electronic sensors for laboratory-on-a-chip detection functions.

These new efforts open up numerous possibilities for the future of microfluidic devices. If these devices can be 3D printed without a clean room, diagnostic tools can be printed by a doctor right in their office or remotely by soldiers on site. „

Michael McAlpine, Senior Researcher, Professor of Mechanical Engineering at the University of Minnesota

But McAlpine said the future was even more compelling.

“Printing 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 body fluids and functions,” said McAlpine, who holds the Kuhrmeyer Family Chair in the Faculty of Mechanical engineering.