Motion capture tech used to 3D print sensors onto moving organs

Unexpected worlds collide in this research project spearheaded by a team of mechanical engineers and computer scientists from the University of Minnesota. The group has developed a 3D printing technique that uses motion capture technology, typically used for moviemaking, to print electronic sensors onto organs that are expanding and contracting. The team says the technique could be used to diagnose and monitor the lungs of patients with conditions, such as COVID-19, which put the health of healthcare providers at risk.

The research, recently published in the journal Science Advances, is based on a 3D printing technique invented two years ago by the same team of engineers and scientists, which is capable of printing electronics directly onto skin. The approach was successfully demonstrated in 2018 by printing directly onto a hand that moved left to right. The updated 3D printing process detailed in the new study integrates a more sophisticated tracking system, allowing for electronics to be printed onto organs as they move.

“We are pushing the boundaries of 3D printing in new ways we never even imagined years ago,” explained Michael McAlpine, a University of Minnesota mechanical engineering professor and senior researcher on the study. “3D printing on a moving object is difficult enough, but it was quite a challenge to find a way to print on a surface that was deforming as it expanded and contracted.”

The 3D printing method was tested with a balloon-like surface that was fitted with motion capture tracking markers, like those used in filmmaking to create special effects. These markers allowed the 3D printer to adapt its printing path, tracking the expansions and contractions of the substrate. The research team also tested the process with an animal lung that was artificially inflated. In these tests, they were able to successfully print a soft hydrogel-based sensor directly onto the lung’s surface. Down the line, the same technique could be used to print directly onto other vital organs, like the heart.

“The broader idea behind this research, is that this is a big step forward to the goal of combining 3D printing technology with surgical robots,” added McAlpine, who holds the Kuhrmeyer Family Chair Professorship in the University of Minnesota Department of Mechanical Engineering. “In the future, 3D printing will not be just about printing but instead be part of a larger autonomous robotic system. This could be important for diseases like COVID-19 where health care providers are at risk when treating patients.”