Tech Briefs Magazine - March 2021 - 48

Manufacturing & Prototyping
3D-Printing of Sensors Directly on Expanding Organs
The technique could have applications in diagnosing and monitoring the lungs of patients
with COVID-19.
University of Minnesota, Minneapolis

echanical engineers and computer
scientists have developed a 3D printing technique that uses motion capture
technology, similar to that used in Hollywood movies, to print electronic sensors
directly on organs that are expanding and
contracting.

The new research is the next generation
of a 3D printing technique discovered two
years ago by members of the team that
allowed for printing of electronics directly
on the skin of a hand that moved left to
right or rotated. The new technique allows
for even more sophisticated tracking to

The technique allows 3D printing of hydrogel-based sensors directly on organs, like the lungs, that
change shape or distort due to expanding and contracting. (Credit: McAlpine Research Group,
University of Minnesota)

3D-print sensors on organs like the lungs
or heart that change shape or distort due
to expanding and contracting.
The researchers started with a balloonlike surface and a specialized 3D printer.
They used motion capture tracking markers - much like those used to create special effects in movies - to help the 3D
printer adapt its printing path to the
expansion and contraction movements
on the surface. The researchers then
moved on to an animal lung in the lab
that was artificially inflated.
They were able to successfully print a
soft hydrogel-based sensor directly on the
surface. The technique could also possibly be used in the future to 3D-print sensors on a pumping heart.
The research is a step forward to the
goal of combining 3D printing technology with surgical robots. In the future, 3D
printing could be part of a larger autonomous robotic system, which could be
important for diseases like COVID-19
where healthcare providers are at risk
when treating patients.
Watch a demo of the technique on Tech
Briefs TV at www.techbriefs.com/tv/organsensors. For more information, contact Rhonda
Zurn at rzurn@umn.edu; 612-626-7959.

3D-Printed Working Heart Pump with Real Human Cells
The functioning human heart pump provides a model to track and trace what happens at
the cell and molecular levels in the pump structure.
University of Minnesota, Minneapolis

cell density for the heart muscle cells to
actually function.
Researchers have optimized specialized ink made from extracellular matrix
proteins, combined the ink with human
stem cells, and used the ink-plus-cells to
3D-print the chambered structure. The
stem cells were expanded to high cell
densities in the structure first and then
they were differentiated to the heart
muscle cells. The researchers achieved
the goal of high cell density within less

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n the past, researchers have tried to 3Dprint cardiomyocytes, or heart muscle
cells, that were derived from pluripotent
human stem cells. These stem cells are
cells with the potential to develop into
any type of cell in the body. Researchers
would reprogram these stem cells to
heart muscle cells and then use specialized 3D printers to print them within a
three-dimensional structure, called an
extracellular matrix. The problem was
that scientists could never reach critical

Cov

ToC

than a month to allow the cells to beat
together, just like a human heart.
This critical advance in heart research shows how the researchers were
able to 3D-print heart muscle cells in a
way that the cells could organize and
work together. Because the cells were
differentiating right next to each other,
it is more similar to how the stem cells
would grow in the body and then
undergo specification to heart muscle
cells.
Tech Briefs, March 2021

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Tech Briefs Magazine - March 2021

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