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Hoelzle's surgical robot brought to life by MAE graduate student and OSU machinist

Mounting for 3D printing surgical arm with a device for practicing minimally-invasive surgery.Mounting for 3D printing surgical arm with a device for practicing minimally-invasive surgery.The ability to print human tissues is hard to fathom for most people. Also, minimally invasive surgery using surgeon-controlled robots is an astounding achievement.

But combining the two ideas and creating a surgical robot that actually prints human tissue while inside the body is reality for two Ohio State researchers.

Dr. David Hoelzle, a professor in the Department of Mechanical and Aerospace Engineering, and Dr. Desmond D’Souza, a surgeon at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, are working in tandem to develop a device that will be able to print soft tissues, bones, and someday even organs inside the human body during surgery.

Andrej with the hand built electrical components for the robot.Andrej with the hand built electrical components for the robot.For the creation of the physical device, Andrej Simeunović, a NSF Graduate Fellow in Ohio State’s Hoelzle Research Lab, and Kevin Wolf, the 3D Printing Laboratory Supervisor, Research Machinist, and Student Shop Supervisor at Ohio State’s machine shop, collaborated to make a surgical robot that is now ready for testing.

“A lot of research is purely theoretical, whereas this project is the opposite. Most of my time is spent making the device and making it work correctly, so we can then use it to demonstrate real-world outcomes,” Simeunović said.  “For me personally, that is something I really value.”

This would be the world’s first endoscopic surgical robotics tool to print tissues inside the body using minimally invasive “keyhole” incisions - something Simeunović finds very compelling.

“This project, in particular, was exciting to me for not just the fact that we are doing something brand new in terms of tissue engineering delivery,” Simeunović said, “but also how many different clinical areas it has the potential to work in.”

For Wolf, this project is a special opportunity.

“I found it extremely rewarding because there were many different factors that had to be taken into consideration when building something this complex,” Wolf said. “Being on the manufacturing side of research, you don’t necessarily get to be very involved with the science behind the project at times.  Making this one that much more interesting to me.”

The project includes working with material scientists and clinicians in the medical school, as well as principles from biology and electrical engineering among many others to bring the robot to life.

Simeunović was in charge of designing and programming the robot and to learn more about surgical robots observed a robotic surgery at the Wexner Medical Center. He also visited two separate times to take measurements on existing surgical robots.

To go about the manufacturing of the actual device, Simeunović went to Wolf in the machine shop just one floor above Hoelzle’s lab. There the two began to prototype and make models with a 3D printer.

After a few prototypes that were smaller, benchtop mockups, Simeunović and Wolf began actually putting a full-sized device together.

The final machine is made up of a metal base and a large robotic arm that has several points of movement. At the end of the robotic arm is a set of four micro motors situated in an area the size of a deck of cards that allows for several degrees of precise motion inside the body. 

The 3D printing device that hooks onto the mechanical arm pictured above.The 3D printing device that hooks onto the mechanical arm pictured above.

The motors also control a plunger that pushes synthetic tissue material down a rod about a half meter long to a nozzle where the actual printing occurs in the body. The combination of motions outside and inside the body allows for safe printing in the body using minimally invasive tools.

Wolf said he spent over 200 hours manufacturing, and then assembling with the help of Simeunović. Simeunović created the code to control the motion and printing of the device and hopes to create a more user friendly interface in the future.


Simeunović highlighted the role the machine shop played in bringing this project into reality.

“It is so helpful to have something like the machine shop and other resources we have both in our department and around the campus,” Simeunović said. “You can very quickly make physical prototypes and find out what about them works and what doesn’t. More importantly, our shop’s teaching and technical expertise as well as their commitment to helping students is invaluable in improving our designs. It’s this synergy that allows for outcomes bigger than the sum of their parts.”

Wolf echoed this sentiment.

“I believe we can certainly fast track research quite a bit more often when researchers decide to collaborate with the manufacturing team early on,” he said.

The device is now beginning testing on tissue-like substrates like agarose and chicken breast, with the goal to move to animal models in the future.

By Jake Rahe, Communications Program Assistant for the Department of Mechanical and Aerospace Engineering